Deep Throat!

wolfen1960

wolfen1960

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I thought that might be an attention getter, and it's accurate too. I've been loading for years, and for about 8 different calibres and never ran into this problem. I am starting to prep some 30-06 loads for a friend, for his rifle, a Rem 700 special edition. I'm not sure (will find out tomorrow) if it is new or not. My problem right from the start is...with one of his once fired cases, when I crimp the Nosler 165 gr accubond slightly and chamber the (unprimed, no powder) case to determine contact with the lands I get very long coal! After about 15 tries, and using a marker to make sure the bullet is NOT being pulled back out of the case I keep getting 3.520" length. By the Nosler, Lyman and Hornady books My max. COAL should be about 3.3". Lyman shows 3.285" for the Nosler 165 gr Balistic Tip. If I load by any of these books I will be about .235" off the lands!! All my rifles are set up to within .015-.050 from the lands and fall very close to book Maximum length.

The magazine in his rifle will allow me to set the bullet closer if need be. Does anyone know if this is normal for a Remington? I've heard of long throats in Weatherby, but even then not .235". Now I'm starting to wonder about the chamber itself, is it correct? His once fired cases, after I had resized them (full length) had to be trimmed about .010-.015", which is about .005 more than I have ever done, and longer than the max case length. These were factory cases. I never trim that off my hotter loads in 300wsm!

Any help would be appreciated. Mark
 
I have a Remington 700 .30-06 with a very long throat.

I recently seated a 180-grain Accubond to 3.450" if memory serves correctly. I normally seat the 168 TSX to 3.400. In both cases, I gave myself more than .025 jump (as measured by the Stoney Point).

Remingtons generally have very long throats. It's not a big deal.
 
Feel free to seat it out, but ensure that you've got the bullet seated in the entire length of the neck (0.325").

With that long freebore, if you have less bullet in the neck, you could get the same situation I did on my military 30-06, where the pressure started to build only to have the bullet exit the neck before it hit the rifling. That caused the pressure to drop rapidly, only to have it rise again milliseconds later when the bullet contacted the rifling - Hangfire. Very disconcerting for the shooter, not conducive to accuracy, and potentially dangerous (it causes a pressure spike).
 
To double check the throat length, seat a flat based bullet backwards in a resized case and chamber it. When the flat base of the bullet contacts the rifling it will push back in the case and that gives a pretty accurate length to the rifling.

I recall back when I had a M-700 .30/06, I seated 165 gr Hornady's out to the lands and the bottom edge of the cannelure was even with the case mouth. Unfortunately those records are all gone, but it sounds like your free-bore is much longer. The rule of thumb I followed when loading ammo for a hunting rifle was to have 1 caliber length of the bearing surface of the bullet in the case neck. More recently, with respect to my hunting rifles, I have disregarded the "rules" and just choose bullets with cannelures or crimping grooves and crimp the bullets in place. This practice has shown no detrimental effect on my field marksmanship, and I believe my ammunition is just a little better as a result.
 
Thanks

I have loaded for a Remington semi auto in 6mm, but never had this clearance (freebore). I will recheck a few times to be sure about last nights results. It's good to hear that it is not just this rifle, but the company that makes them this way. Again thanks for the help. Mark
 
I have a 700 SSDM Remington in 30-06. The COL that gives me .020" clearance to the lands is 3.445" In my experience long throats are quite common with 700's. Fortunately, the 700 also has a nice magazine length, so it is not near the issue of some shorter magazined rifles. Seat it out, always maintaining sufficient bullet in the neck, and shoot away. Regards, Eagleye.
 
Done

As Eagleeye stated the magazine is very long, so I loaded these Accubonds to 3.430" (still leaves pretty much the whole length of neck holding the bearing surface, but 0.090" jump yet) and worked up to the max load by the Nosler book with IMR4350. This is the first rifle that I've reached max on, and gotton the same velocity as the book. With my 300 wsm I reach their max velocity before the top loads in most cases and show pressure signs if I push much past (even though I'm still below the max charge).

I do have one complaint about my friends rifle though, and it is similar to the experience I've had with a couple of Remingtons...what a rotten trigger! I honed my Rugers trigger and have both it and my Accutrigger on my Savage at about 2-1/2 lbs. They break crisp and very little if any creep. I just about need to hang a bag of spuds off this Rem trigger to make it shoot. I think that the 1-1/2" to 1-3/4" groups (only 6 groups so far) are as good as I will be with this setup, but if he gets some trigger work done he should have a shooter.
 
The Remington throat is long so as to reduce pressures. A safety feature. Think of it as a chamber designed by a lawyer.

Seat the bullets out further and increase the powder capacity. With a spitzer bullet you might not be able to seat it long enough to be close to the rifling and still be able to fit the magazine.

If you hunt, make sure the rounds easily fit the magazine and still feed OK at the longer length.
 
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