Looking for some 7mm info

[dfrombc]

Recently I've acquired a Tikka M65 in 7mm rem mag. The stock was cracked so I've got a Mcmillian on the way for it. So while I'm waiting for the stock I got to thinking about replacing the 22'' barrel ( which apparently shoots very well, I just don't think I'll get the velocity I'm after). I would like to push 180's into the 3000fps range accurately. My purpose for the gun will be large game at extended range and some long range plinking. Now at first I was thinking about getting a reamer from gunwerks and going with their 7LRM. I know the possible shortfalls of going with a chambering like this ( component availability.....) but it sounds pretty impressive regardless. No belt, long neck, high velocity with moderate pressures and accurate to boot.

While looking into my options I've also run across a lot of people who claim 2900-3000 fps with 180's from the 7mm rem mag. Usually with a 26'' or longer barrel but apparently it can do it. So my questions are these....

What are you experiences with the 7mm rem mag with 180 gr class bullets? What kind of velocities are you getting?

If people are getting into the 3000fps area, how hard are you pushing? Whats the brass life like?

Any real accuracy issues with the 7mm rem mag? ( Some claim the short neck to be detrimental)

I've also read about the belted case causing sizing issues after a few firings. Apparently the cases can bulge above the belt and sometimes FL dies don't size this area enough. Any truth? This is my first belted magnum.

I'm not afraid of trying something new/ different but if what I'm looking for can be accomplished with the 7mm rem mag I won't bother with the 7mm LRM. On the other hand I'll be re-barreling regardless so now's the time to figure out if I wanna stick with the rem mag or not.

Any advice would be appreciated.

 

[c-fbmi]

Never played with 180s, but 3K with 175s from a 26" tube is easy. Never had a problem with belted cases and I shot a 7 RM for many years, I shoot primarily belted cases and have never experienced any problems as you have indicated. I believe the problem lies more with cheap dies than with belted cases. If the 7 RM doesn't do what you want, you can always rechamber to 7mmX300WM or 7mm STW or 7mm RUM, without cutting back the barrel.

 

[shorttrac]

I have not shot 180's but my experience is with 145 speer btsp and I push them to 3300-3350 with 100v or 7828 or H1000. Brass life is good. extraction is effortless, no extractor marks ect. It is pushing it for sure but not unsafe as far as I am concerned with 26" tube. This was tested in a styer pro-hunter, Savage model 12, Sako 75, Savage 114. The latter 2 had 24" tubes and were around 3275fps. Just thought I would mention this as it is not just from one fluke barrel. Just observing the difference of 35 grains of lead I would think would account for 250-300fps putting you right at 3000 and maybe more with good case life. Also nosler manual shows 175 grain bullet at 2970fps with rl-22 as the most accurate load and powder tested at that pressure, all in a 24" tube. add 2" of barrel and you are at your goal without exceeding max. I think 3000 is definitely attainable.

 

[dfrombc]

Never played with 180s, but 3K with 175s from a 26" tube is easy. Never had a problem with belted cases and I shot a 7 RM for many years, I shoot primarily belted cases and have never experienced any problems as you have indicated. I believe the problem lies more with cheap dies than with belted cases. If the 7 RM doesn't do what you want, you can always rechamber to 7mmX300WM or 7mm STW or 7mm RUM, without cutting back the barrel.

I'm limited to about 3.4'' COAL by the mag. The STW was my first thought but most seem to load it to 3.6''+. I didn't want to pick a cartridge that would be handicapped by the mag length. Would seating the bullets deeper hinder it much / at all?

 

[c-fbmi]

I'm limited to about 3.4'' COAL by the mag. The STW was my first thought but most seem to load it to 3.6''+. I didn't want to pick a cartridge that would be handicapped by the mag length. Would seating the bullets deeper hinder it much / at all?

You might want to consider the 7mm-300 Win Mag, I built one years ago and it equaled the STW, more efficient than the STW and significantly more capacity than the 7 RM. Easy to get brass and easy to load for with 7 RM dies and 300 WM sizer die, you don't need special dies, and there is no forming process other than to neck down the 300 to 7mm.......that's it, just neck down and load. COAL should work nicely through the 3.4" magazine and you'll be the only kid on the block with one !!!
Don't worry about the short neck on the magnums, the 300 WM held the 1000 yd record for several years so what does that tell you? Your loading expertise will have way more effect on accuracy than the length of the neck. Also with the 300 WM as a parent case you can use which ever brand of brass you like and know there will always be a ready supply. The luxury of basing on the most popular belted magnum caliber/case in history, an endless supply of good, cheap brass.
I have had several wildcats based on the 300 WM case and have a 9.3 right now, it is a magic case and all my wildcats exceeded my expectations. As I recall my 7X300 WM shot 160s into 3/4" at 100 mtrs and clocked just shy of 3400 fps in a 24" tube. I used all W-W brass which I find to be lighter and tougher than any other, and I usually get 75-100 fps more from W-W cases than say R-P. Just a thought.................

 

[dfrombc]

You might want to consider the 7mm-300 Win Mag, I built one years ago and it equaled the STW, more efficient than the STW and significantly more capacity than the 7 RM. Easy to get brass and easy to load for with 7 RM dies and 300 WM sizer die, you don't need special dies, and there is no forming process other than to neck down the 300 to 7mm.......that's it, just neck down and load. COAL should work nicely through the 3.4" magazine and you'll be the only kid on the block with one !!!
Don't worry about the short neck on the magnums, the 300 WM held the 1000 yd record for several years so what does that tell you? Your loading expertise will have way more effect on accuracy than the length of the neck. Also with the 300 WM as a parent case you can use which ever brand of brass you like and know there will always be a ready supply. The luxury of basing on the most popular belted magnum caliber/case in history, an endless supply of good, cheap brass.
I have had several wildcats based on the 300 WM case and have a 9.3 right now, it is a magic case and all my wildcats exceeded my expectations. As I recall my 7X300 WM shot 160s into 3/4" at 100 mtrs and clocked just shy of 3400 fps in a 24" tube. I used all W-W brass which I find to be lighter and tougher than any other, and I usually get 75-100 fps more from W-W cases than say R-P. Just a thought.................

I'm starting to like the idea of the 7-300 win mag. It sounds like what I'm looking for without the having to worry about special dies or expensive brass. If I understand correctly I can FL size with a 300 win mag die ( I'm thinking bushing die with appropriate 7mm bushing) and seat with a 7mm rem mag die? Would it make sense to neck down brass with the FL die and decrease bushing size until I get where I need to be? This would be my first time playing with case forming (aside from fire forming AI cases)

 

[sunray]

Max speed for a 180 is just under 3,000 fps with a max load of Retumbo, according to Hodgdon. Likely out of a 26" barrel, but they don't give that. Suggest you surf around the assorted component/powder maker's sites and see if there is any powder that does what you want.
If you're going to change the barrel anyway, your options are pretty much open to whatever you really want. Mind you, you might have an issue finding a barrel for a Tikka, unless you spend the money on a completely custom built barrel. More options open with that.

 

[timmy204]

I'm starting to like the idea of the 7-300 win mag. It sounds like what I'm looking for without the having to worry about special dies or expensive brass. If I understand correctly I can FL size with a 300 win mag die ( I'm thinking bushing die with appropriate 7mm bushing) and seat with a 7mm rem mag die? Would it make sense to neck down brass with the FL die and decrease bushing size until I get where I need to be? This would be my first time playing with case forming (aside from fire forming AI cases)

Your not going to gain much by going to a longer case when your restricted to 3.400 col, the bullet will just be seated into the case deeper eating up your powder capacity. A fatter case like the 7mm LRM might be a better way to go.

 

[dfrombc]

Your not going to gain much by going to a longer case when your restricted to 3.400 col, the bullet will just be seated into the case deeper eating up your powder capacity. A fatter case like the 7mm LRM might be a better way to go.

Something to consider for sure. I could be over thinking this whole thing as well. It sounds like the rem mag can get me pretty close to where I want to be. I could always have a 26'' barrel screwed on and see where I end up. I know I'm splitting hairs looking for another 200 - 300fps but thats what being a gun nut is all about!

Please keep the advice coming.

 

[1899]

You are not going to get 3000fps with a 180gr or 175gr out of a 22" barrel at anywhere near SAAMI max pressure. Even 2900fps would be doing well. On the other hand the 100fps won't make any difference. If you are looking for more velocity then consider the 168gr LRAB combined with IMR 7828, RL25 or Ramshot Magnum. The 7mm RM has been my main hunting cartridge for over 25 years now and it has always performed well. With respect to accuracy, here is a 3 shot group out of a factory sporter (those are 1" squares):

 

[shorttrac]

Something to consider for sure. I could be over thinking this whole thing as well. It sounds like the rem mag can get me pretty close to where I want to be. I could always have a 26'' barrel screwed on and see where I end up. I know I'm splitting hairs looking for another 200 - 3fe00fps but thats what being a gun nut is all about!

Please keep the advice coming.

you could get another couple hundred fps with a RUM or STW at the expense of 20 more grains of powder and considerably more recoil. The .300winx7mm sounds interesting for sure. I think everyone has a different threshold for running max loads. I think if I I get 4-5 loads before the primers wont hold for me that is safe. Others think if you get any case head expansion and don't get 20 reloads per case that is not safe. To each there own. I feel the 7mm rem will do what you want easily and safely. Factory 175s run 2860 in a 24" barrel and my experience shows 26" will get you another close to 100fps and that at factory downloaded pressures. Bigger case is not necessary but nessesity is the last thing I think of when guns are concerned.
I did as everyone said years ago with .338 win mag and upgraded to a RUM when I was pushing the threshold for pressure to get big velocity. The win shot great but all advice lead me to believe that my gun was going to explode at any minute because we all know SAAMI says the limit is 62000psi and if you load 62001 your rifle will explode. The Rum did get the velocity I wanted but rattled my fillings loose and made shooting uncomfortable. I now own the win again and couldn't be happier with it, albeit 150fps slower but don't tell the moose that.

 

[c-fbmi]

OP, the other nice thing about the 7mm-300 WM is that you can easily get your needed 3K fps, with a 24" barrel and do it at lower pressure than the 7RM. Although the bullets will be seated deeper there is still a significant gain in powder capacity with the 300 case. All I ever did for loading was to full length size the fired 300 brass in the 300 FL die, then run it up into the 7 RM sizer die until it necked down far enough to chamber and then set up and used the 7RM seater die to seat the bullets. I have never owned or used a collet die so I cannot advise you on how to go about using one of them. If you want to go to a 26" tube you can expect an honest 150 fps gain on the 7 RM case using the 300 WM case, the same goes for the 24" tube, you can still expect a 150 fps gain on the 7 RM case or you can reduce pressures and run 3K fps and your cases will last forever. But if you're like shorttrac and me 3-5 loads from a case is safe so why download !!! They make them brass cases everyday in the US, by the thousands, so don't be afraid to load 'em up....
Remember higher velocity doesn't really make that much difference in trajectory, as 50% of the guys on here will tell you, but it does make a difference in wind drift and downrange energy and besides if it'll do 3200 fps why not do it?

 

[stubblejumper]

But if you're like shorttrac and me 3-5 loads from a case is safe so why download !

You may consider it safe, but in order to have cases unusable after only 3-5 rounds, unless the cases are softer than normal, the chamber pressure would be well above the SAAMI pressure for the cartridge.

 

[Doug]

You may consider it safe, but in order to have cases unusable after only 3-5 rounds, unless the cases are softer than normal, the chamber pressure would be well above the SAAMI pressure for the cartridge.

Some folks live on the edge, others live back from the edge................and the lawyer-friendly documents of today would put a person quite a ways back from the edge methinks. I don't think this forum is like a bunch of people yelling "JUMP, JUMP!!!" so much as folks saying, "well, this worked for me and you might like to look at it."

JMOYMV

Doug

 

[stubblejumper]

Some folks live on the edge, others live back from the edge................and the lawyer-friendly documents of today would put a person quite a ways back from the edge methinks.

I have witnessed loads published in recent manuals, that resulted in significant pressure signs, at below the maximum load listed in the manual. Contrary to what some people may think, there isn't a large safety factor built in to all loads listed in today's loading data.

I don't think this forum is like a bunch of people yelling "JUMP, JUMP!!!" so much as folks saying, "well, this worked for me and you might like to look at it."

In some cases, I see it more as" I push the limits significantly, and I haven't blown up a firearm YET"

Some people get away with pushing to the extreme for quite some time, while others, are not so lucky.

 

[Doug]

I have witnessed loads published in recent manuals, that resulted in significant pressure signs, at below the maximum load listed in the manual. Contrary to what some people may think, there isn't a large safety factor built in to all loads listed in today's loading data.



In some cases, I see it more as" I push the limits significantly, and I haven't blown up a firearm YET"

Some people get away with pushing to the extreme for quite some time, while others, are not so lucky.

Yep, like I said, JMOYMV or Just My Opinion, Yours May Vary. I like to be exposed to new ideas and take them, or not, as I decide. I don't go out and copy somebody's Internet recipes without doing some work on my own - and anybody who would just take information uncritically from the Internet might just be a Darwin Award recipient in waiting.

Doug

 

[timmy204]

Something to consider for sure. I could be over thinking this whole thing as well. It sounds like the rem mag can get me pretty close to where I want to be. I could always have a 26'' barrel screwed on and see where I end up. I know I'm splitting hairs looking for another 200 - 300fps but thats what being a gun nut is all about!

Please keep the advice coming.

A 26'' barrel will help for sure. You could go 7mm rem mag if your set up for it already, then if your not satisfied you could have have it rechamber to 7mm/300.

 

[c-fbmi]

stubblejumper.......there are a number of reloading faux pas that can create pressure signs below max book loads, COAL too long jamming bullet into the lands, undersized brass with too much headspace will give false pressure signs.
I've said this before here, if the brass case holds the pressure the load is safe.........the action steel and bolt steel will withstand 3 times the pressure of the brass case, without catastrophic failure. The brass case limits all loads to a significantly safe margin in all modern bolt actions. I have proven this myself by trying to blow up a 700 action, didn't have the balls to go beyond what I did but had to remove the barrel to get the action to open, and it didn't set the lugs even 1 thou. If perchance one was able to overload a case to the point of destroying the action the worst thing that would initially happen would be lug set, which disables the action and ruins it, this happens way before catastrophic failure and potential lethality. Although I won't say it's impossible to load to a point that would shear lugs and make the rifle potentially lethal, I will say it is virtually impossible with any powder that would normally be used in that cartridge. Even a steady diet of MAXIMUM loads will cause other problems, rendering it useless, long before it will become a grenade.

 

[quarterman]

I have used the 7mm rem mag for a good portion of my life. It easy to handload for. I have never had any of these so called issues with any belted magnums. I have not used 180s out of any of my 7mms, but Ive had very good luck with bullets ranging from 140 grains to 175 grains. With 168 grain berger vlds fed 215 primers and retumbo I get 3000 fps with the powder charge and seating depth my rifle likes. My rifle has a 1 in 9 twist 26 inch barrel. I would think 2900fps should be obtainable without pressure issues with a 180 grain. If you dont mind the extra barrel length you could always go with a 28 inch barrel and gain a little more velocity

 

[stubblejumper]

stubblejumper.......there are a number of reloading faux pas that can create pressure signs below max book loads, COAL too long jamming bullet into the lands, undersized brass with too much headspace will give false pressure signs.

Who says the pressure signs weren't a true indication of excessive pressure? I observed excessive case head expansion, and my chronograph told me that I was exceeding the velocities listed in the manual, so the pressure could very likely have been excessive. Now if you choose to believe that loading to produce 80,000-90,000psi or more is safe, then by all means, keep loading to those levels, and perhaps you won't have a case rupture, or have something fatigue over time, and let go in your face. However, don't pretend that just because you haven't had a failure yet, that loading to those pressures is safe.