H 322 starting load 6ppc

[wmdron]

About a month ago I finished fireforming some Lapua .220 russian for my Cooper M21 6ppc 12 twist. I used 26g of H322 and a 68g Barnes Matchburner FB with good results. I would like to continue along these lines with the H322 and the 68g Matchburners, so I was thing of a starting load of 25g to 25.5g of H322. What do you guys think ? Thanks.

 

[Tim Singleton]

Im sure others with more experience than i will respond. maybe Boyd will give an opinion.
In my experience that's a little on the light side. my 6ppc did better with H322 in the 27.5 gr and up range

 

[LawrenceHanson]

You will be very safe starting out with your proposed load. With my components, I top out at 29 grains of H322 in the 6ppc. This charge is near 100% load density.

 

[GSPV]

Are Match Burners solid copper bullets?

If so, you might have to reduce powder charge from what we normally use with the lead core bullets.

 

[JohnHenry]

The Hodgdon max(50,000 CUP) with a 70 grain bullet in a 6PPC is 26.5 grains of H322. Remember the Cooper model 21 is a small action(.55" bolt dia), not a custom benchrest action capable of taking a higher bolt thrust then a Cooper model 21. Just look at the size difference in the bolt lugs between the actions. Be safe, leave the higher pressure loads to the benchrest competitors with the custom actions.
It is interesting to note that per their web site, Cooper no longer chambers the model 21 in 22 or 6PPC. Wonder why?

 

[CatShooter]

The Hodgdon max(50,000 CUP) with a 70 grain bullet in a 6PPC is 26.5 grains of H322. Remember the Cooper model 21 is a small action(.55" bolt dia), not a custom benchrest action capable of taking a higher bolt thrust then a Cooper model 21. Just look at the size difference in the bolt lugs between the actions. Be safe, leave the higher pressure loads to the benchrest competitors with the custom actions.
It is interesting to note that per their web site, Cooper no longer chambers the model 21 in 22 or 6PPC. Wonder why?

The strength of modern actions so far exceeds what is needed by ANY of the cartridges, that pressure (even max loads) are not a consideration.

In the litigative world that we live in, these people are not stupid. There is a 20x + safety factor built into any modern action.

If they do not offer the PPC family, I assure you that it is sales (or lack thereof) that drive that decision.

The Cooper is NOT a benchrest rifle, and there is little market for the PPC cartridges outside of that market. FOr what people buy the Cooper for, there are better, OTC cartridges available.

 

[wmdron]

I basically want to know if I am at a safe starting point having found very little to compare to in my searches. Match Burners are lead core bullets. My Cooper M21 I bought used from a local gunshop, probably from someone wanting to move into benchrest in a more serious manner. Although not a benchrest rifle my Cooper is a nice rifle none the less and I have had fun shooting it and have learned quite a bit loading for it. I don't regret my purchase in the least. I do need some help from time to time and for that I rely on the generosity of this forums members. Thanks again for the help and if anyone else would like to weigh in on my question please do so. Ron...

 

[JohnHenry]

wmdron, I think your proposed starting point is fine. I shoot a Cooper model 21 in 22PPC. As you said, not a benchrest rifle but a very nice and accurate rifle. I choose not to exceed published max loads in my Cooper PPC. Under a prior owner, I had the occasion to visit Cooper a couple of times. I know a concern of theirs was the tendency of some to try published match loads in their Cooper PPCs. I do not suggest that these higher pressure loads would result in catastrophic failure of the action, but could way short of the yield point contribute to increased bolt deflection and case stretching and a very sticky/difficult bolt lift. The amount of bolt deflection is among other factors a function of bolt thrust and the size and number of bolt lugs. You may find the following article by Dan Lilja of interest. http://www.riflebarrels.com/articles/custom_actions/bolt_lug_strength.htm

 

[WyleWD]

About a month ago I finished fireforming some Lapua .220 russian for my Cooper M21 6ppc 12 twist. I used 26g of H322 and a 68g Barnes Matchburner FB with good results. I would like to continue along these lines with the H322 and the 68g Matchburners, so I was thing of a starting load of 25g to 25.5g of H322. What do you guys think ? Thanks.

I too have a "factory 6ppc". I noted that in your original post that you used 26grains to fireform with. There are a LOT of variables that come into play (primer type, neck tension, seating depth, barrel length) to name a few, but if you used 26 to start out with, you should be fine to start at the vicinity you posted (25-25.5). With that 12 twist, I'm guessing that you won't go much higher than 26 before you find a sweet spot that will provide the accuracy you can be very happy with. WD

 

[wmdron]

Thanks John and Wyle for the additional input, Nice read by Dan Lilja. It has taken me awhile to get to this point where I now have the knowledge and skill to load for this rifle. I tried to do my homework, I read a few books, Precision Shooting, Tony Boyers rifle book of accuracy to name a couple. And I asked questions on this site, I owe thanks to the people who have helped me along and continue to do so and thanks to this site for being such a great resource which I gladly support. I bought my Cooper to have a little fun and to learn more about reloading. I have no intention of pushing things beyond the max published loads and am quite content with a nice accurate and safe load. My fireforming load shot a five shot group of about 3/8" at 100 yds which is one of the best groups that I have ever shot. I can't wait to load up and try again when I get the time. Well 25g H322 Barnes 68g it is then for starters. Many thanks, Ron...