Mountain Rifle - Kimber 84M Proof Research .308 Win

[MCMXI]

I’d try 5 rounds each of the ones you have in inventory.

I know this gets down to the nitty gritty of load development but the results are often surprising

I will. I also realized that I have a box of Winchester WLR primers so my test will include the following.

Federal GM210M
Federal GM215M (magnum)
CCI 200
CCI 250 (magnum)
Wolf PP
Winchester WLR

 

[redneck2]

If you start running the numbers, you soon figure out that there are literally hundreds of thousands of combinations of powders, bullets, primers, and seating depth.

You’re hope is that you find something acceptable in a short time. And, it isn’t like only one works. Maybe 1/3rd them may be good enough. Maybe more, maybe less. It seems every rifle is a world unto itself, though some brands and calibers are more/less finicky than others

 

[Nature Boy]

I will. I also realized that I have a box of Winchester WLR primers so my test will include the following.

Federal GM210M
Federal GM215M (magnum)
CCI 200
CCI 250 (magnum)
Wolf PP
Winchester WLR

Looking forward to seeing it.

Double check the diameter on those WLR primers. I’ve found them to be undersized

https://www.thehighroad.org/index.php?threads/checking-primer-pocket-size.814939/#post-10438294

 

[MCMXI]

If you ask Mr. Google, you may find something on primer bristance. It shows the flame pattern given off by different brands of primers. It varies a LOT.

When I tested five different primers for a 6.5x47mm Lapua load (link above) the average velocity of the five loads only varied by 13 fps. I'm wondering if that's indicative of 100% powder burn across all loads. According to QuickLOAD the 175gr LRX load is burning up 96% of the powder in a 24" barrel so maybe I'll see a greater spread in this test. Sure would be nice if one of the primers maintains precision but bumps velocity a little while lowering ES numbers. That would be a win, win, win.

 

[redneck2]

Years ago Handloader published an entire article about primer performance. It showed the flame pattern of various brands. The variations were pretty substantial. Also, there was a difference in the composition of the actual compound used.

 

[MCMXI]

I placed a special order a few weeks ago for an EGW Picatinny rail with 30 moa (8.7 milrad) of cant. The custom rail was an additional $25 but worth it since it allows me to maximize the amount of vertical adjustment. The PST only has 20 milrad of vertical adjustment from stop to stop. With the 30 moa rail, it will shift the center (100 yard zero) to a much better 16.2 milrad up and 3.8 milrad down which would give me sufficient adjustment to get out to 1200 yards if necessary. The rail arrived yesterday and I was surprised to see that they simply machined a 20 moa rail and provided some shorter screws for the front bridge. For $100 I was expecting a finished part that was fully anodized. I took some measurements, did some calculations and came up with a 27 moa cant on the rail. Oh well, I got it installed, dialed in 8.7 milrad down and will shoot today or tomorrow to see if my zero is close. The new rail certainly moved the objective bell closer to the barrel which looks better.

I ordered some 5 and 10-round 7.62 AC PMAGs which arrived last week. I really like them and they certainly feed a lot smoother than the Accurate-Mag AICS clones that I've been using. I've been busy with other things so haven't got back on load development but should have some updates soon.



84M Proof shown with EGW 30 moa rail, 5-round 7.62 AC PMAG, Harris bipod and SilencerCo Omega suppressor

 

[horsemen61]

That's a clever solution ... nice job!




Thanks @LoonWulf . The gunsmith at GroveTech told me to make sure that the cup is slightly proud of the stock to prevent the QD fitting from rubbing on the stock so I did my best. Devcon takes 24 hours to fully cure so it won't be until later today that I can get a sense of how much faith I have in the rear cup. Personally, I like the QD cup concept for the reasons already mentioned, and the QD sling swivel stud is a bonus since it allows the use of a Harris bipod.




Probably H&M Blacknitride. I can get four to five receivers/bolts nitrided for $250 total so I plan on sending them five receivers at the moment and possibly one barrel.

http://blacknitride.com/

can you let me know how that goes I have a rifle I am thinking about having this done to I just worry about the accuracy and if it will affect it at all

 

[MCMXI]

can you let me know how that goes I have a rifle I am thinking about having this done to I just worry about the accuracy and if it will affect it at all

Will do. I'm getting close the point where I want to send four or five receivers out to H&M Blacknitride.

 

[horsemen61]

Will do. I'm getting close the point where I want to send four or five receivers out to H&M Blacknitride.

Any news?

 

[MCMXI]

@horsemen61, no updates at the moment. I did manage to replace a target at 700 yards that was stolen by some loggers. They'll have a much harder time of stealing my new target, not that I have much money into it.

 

[MCMXI]

I drilled a couple of holes in some T-posts, then puddle welded nuts onto bolts, used chain from commercial snow chains (free) and drove the T-posts at least 4 feet into the ground. The loggers will have to work if they want this target.

700 yard 12" x 12" target

 

[horsemen61]

@MCMXI any updates?

 

[MCMXI]

None yet. I did put a deposit down on a new powder dispensing system (trying to keep up with @Nature Boy and @Walkalong), got sidetracked with the Tikka that I bought from a friend and started a new job. It'll probably be a while before I do any more load development with the Kimber/Proof. I'll get back on it once it cools off a bit.

 

[horsemen61]

@MCMXI did you end up doing the black nitride?

 

[MCMXI]

@MCMXI did you end up doing the black nitride?

Not yet. I want to send at least four receivers and bolts in including the one shown in this thread along with an 8400 WSM, 8400 Mag and maybe two more 84M receivers. I need to get that rolling ASAP.