Question for Cooper owners?
- Thread starter deertroy
- Start date
I also just got my Cooper in 6mm Rem.On its first range session it was living up to Cooper's 1/2 moa claim,on some of the loads I tried.I fired 20 rounds and then cleaned it.The groups opened up and then settled down after 10 or so rounds.After a couple more range sessions with good results and 40 rounds fired,I cleaned it again.The next groups opened up until several rounds were fired from the clean barrel.
So,enough with the cleaning I say .GJ
I'm using rem mostly,and some win brass all fls until I get it fireformed for the Cooper.
So,enough with the cleaning I say .GJ
I'm using rem mostly,and some win brass all fls until I get it fireformed for the Cooper.
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Deertroy, I conducted some research in my reloading manuals and cyber space, found that Reloder 15 and Varget are very popular powders with the 140 grain spitzer bullets. If I had this cartridge I would start with these two powders....................just thought that I'd mention it. Purchase some Lapua brass in 308 winchester and neck it down...............it won't hurt.
I have an idea what might work in the 7mm-08. I purchased my first one in 1983 a few years after Remington introduced it commericially. This is my sixth 7mm-08 and I've handloaded for all of them. I'm just saying this to give some background.
The scope is a Leupold VX-III that has been proven on other rifles. I have a concrete shooting bench that's solid. I'm certainly not a benchrest shooter but I am capable of shooting good groups. The 45-70 certainly isn't a 300 RUM but it does recoil more than a 7mm-08. My GBL will shoot. Just to rule some things out.
I was mostly looking for input from other Cooper shooters to see how there rifles preformed during the first 20 or so rounds down the tube. I do appreciate the other points mentioned as I'm certainly not above over looking something that I may have missed.
The scope is a Leupold VX-III that has been proven on other rifles. I have a concrete shooting bench that's solid. I'm certainly not a benchrest shooter but I am capable of shooting good groups. The 45-70 certainly isn't a 300 RUM but it does recoil more than a 7mm-08. My GBL will shoot. Just to rule some things out.
I was mostly looking for input from other Cooper shooters to see how there rifles preformed during the first 20 or so rounds down the tube. I do appreciate the other points mentioned as I'm certainly not above over looking something that I may have missed.
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To respond to your question and getting to the point, I never had groups as large as yours from my Coopers. There was nothing over an inch from the 7mmSTW, 280 AI and the 6.5x284 Norma when first taken to the range to develope loads and to break in the barrel..............my way, not Coopers way. My way is load develope when breaking in the barrel. Three shots, then clean. This usually is repeated 20 times during the first outing.................lots of fun!I have an idea what might work in the 7mm-08. I purchased my first one in 1983 a few years after Remington introduced it commericially. This is my sixth 7mm-08 and I've handloaded for all of them. I'm just saying this to give some background.
The scope is a Leupold VX-III that has been proven on other rifles. I have a concrete shooting bench that' solid. I'm certainly not a benchrest shooter but I am capable of shooting good groups. The 45-70 certainly isn't a 300 RUM but it does recoil more than a 7mm-08. My GBL will shoot. Just to rule some things out.
I was mostly looking for input from other Cooper shooters to see how there rifles preformed during the first 20 or so rounds down the tube. I do appreciate the other points mentioned as I'm certainly not above over looking something that I may have missed.
Of the 3 coopers I have not had groups that large from any if i did my part. I didn't do the recommended break in on any of them. I don't notice any excessive fouling on them. I would load up another batch of ammo and give it another try. I found 140 gr berger vlds to shoot very well in my 280 custom classic.
Its the ammo, Use the load specified on the factory shot target. Just because a rifle will put a certain load into one hole dosent mean it will do it with everything. When I bought my cooper, I bought a couple boxs of factory hornady ammo for use in the break in procedure. They would all group into abou a inch and a half. I later loaded the brass with the load specified on the factory shot target, and after adjusting the seating depth I was able to obtain 3 shot groups which are under the half moa groups gaurenteed by cooper. I have never had any excessive barrel fouling either. A good load to try is the accuracy loads out of the sierra loading manual, these loads usually work well out of most rifles and could help you get on track to some better groups
The only problem with that theory, is that Cooper generally uses Sierra Matchkings for their test ammunition. If you intend to hunt big game, you will likely want to be using a hunting bullet. Fortunately, I have been able to work up a load with hunting bullets, for each Cooper that I intend to hunt big game with. In my rifles, the Barnes TTSX shoots very accurately, as does the Nosler Accubond.
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my cooper excalibre in 280 is one of my least fussy rifles. it will shoot 120and 140 tsx, 140 ab, 160 sierras very well with little devopment. the worst load i tried was under 1.5 the tsx easily shoots under an inch with the 120tsx mostly arround half an inch. loaded too hot the 120 tsx will open to an inch or so.
Often sierra makes match and hunting bullets in the same weight and they usually shoot about the same with the same powder and primer combo and a similar seating depth. barnes ttsx bulets are usually very consistant and Ive had great luck with them in most rifles Ive used them in. The accubonds are a great choice too. Could be the shooter if the sierra, barnes and noslers dont work
Cooper uses the 130gr Matchking to test the 7mmstw rifles. I would never use any Sierra 130gr bullet in a 7mmstw to shoot moose or elk. In fact, there isn't a 130gr .284" Accubond or 130gr .284" TTSX either , so a person has to go with a different bullet weight to find a suitable hunting bullet. That is the one flaw with using the 130gr matchking data to determine a hunting load for that chambering. That given, I haven't had a problem finding an accurate load in any chambering.
