7mmmountaineer
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Post by 7mmmountaineer on Jan 16, 2015 18:16:02 GMT -5
I might be going off on a fools errand here but I will try it. I have 200 pieces of Lapua 308 small primer pocket brass. I am thinking about necking this brass down to 7-08 Rem and trying it. Since I have no small Fed Match primers and Natchez (starting to love that place) has the BR4's I ordered some. So my questions/concerns are as follows. Will this change the pressure enough to cause me concern? Will this be a good experiment to take on? Dose this sound like a fools errand? Would you try this? I will be trying this on a rifle I have off at Hart Barrels being done. It is a 9 twist #5A Douglas taper finished at 24 inches going in a Boyds laminated stock that is going to have the barrel and action pillar and glass bedded, Remmy action with a Rifle Basix trigger set at 3lbs topped with a Nikon Monarch 3 4x16x50.
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Post by krwada on Jan 16, 2015 18:23:21 GMT -5
Hello Chuck;
1. Would I try this?... Heck yeah!
2. Is this a fool's errand? ... given your comments here and history, I would say no.
3. Pressure concerns? ... Yes, from what you are saying ... I would hazard a guess that the pressure would be a tad bit higher than a standard 7mm-08
Some things to think about.
1. Work up using the chrono. Your best bet will be to compare your results against the MV with standard 7mm-08 profiles
2. You may want to turn the necks on your necked down brass
3. Once you have necked down, do not forget to anneal and fireform.
Please post your results when you go through this. There is a whole ton of stuff you will need to do for this project.
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Jan 16, 2015 18:34:18 GMT -5
Ken I got all the gadgets and gizmo's for neck turning for X-Mass and my B-day so I will finally get to try this. Needing a new chronograph looking for a good one now. I am going to stock up on a few things before hand. I also just ordered a #8 of H414 and W760 they have both always worked for me before. Norma brass just incase this doesn't work out. Some 162 A-Max's (as soon as I can find them) and 168 SMK's will be the biggest fodder for this rifle. I am gonna try my hand at some local shooting competition 400-650yds mostly prone.
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Feb 8, 2015 21:36:19 GMT -5
Decided to try this with one of my current 7-08 what can I say it was a nice weekend and I was bored. Early results were encouraging mind you I purposely stayed low with my test loads none of them above a mid weight charge per Nos #7. I did duplicate the loads I tried with my standard LR primer brass. One thing I saw right off the bat I did gain velocity ever so slightly. The SD and ES numbers dropped slightly also. The following is what I tried small primer first.
140gr Nos BT with IMR 4895 37-38.8gr Lapua 308 (necked down) CCI BR4 primers my Rem 700 SPS Varmint with a 24" factory tube in .3 steps up the ladder:
37.0gr 10 shot string ave velocity was 2597fps with an SD of 15 and an ES of 22 37.3gr 10 shot string ave velocity was 2612fps with an SD of 15 and an ES of 20 37.6gr 10 shot string ave velocity was 2626fps with an SD of 17 and an ES of 23 37.9gr 10 shot string ave velocity was 2639fps with an SD of 14 and an ES of 18 38.2gr 10 shot string ave velocity was 2652fps with an SD of 15 and an ES of 21 38.5gr 10 shot string ave velocity was 2667fps with an SD of 12 and an ES of 19 38.8gr 10 shot string ave velocity was 2682fps with an SD of 17 and an ES of 21
Same gun same bullet and powder with Norma Brass and CCI 200 primers:
37.0gr 10 shot string ave velocity was 2588fps with an SD of 19 and an ES of 26 37.3gr 10 shot string ave velocity was 2600fps with an SD of 18 and an ES of 24 37.6gr 10 shot string ave velocity was 2618fps with an SD of 18 and an ES of 24 37.9gr 10 shot string ave velocity was 2631fps with an SD of 19 and an ES of 27 38,2gr 10 shot string ave velocity was 2646fps with an SD of 20 and an ES of 29 38.5gr 10 shot string ave velocity was 2660fps with an SD of 17 and an ES of 22 38.8gr 10 shot string ave velocity was 2673fps with an SD of 18 and an ES of 22
BR4 SD ave was 15 ES ave was 20.6 (rounded off) CCI 200 SD ave was 18.4 (rounded off) ES ave was 24.9 (rounded off)
Small sample size to be sure but I will try this again in a few weeks with 2 other powders Alliant 2000MR with 145 Spr BTSP's and with H414 and 140gr Nos BT's and see how those results compare. Note I did not do a side by side accuracy test this time around just wanted some raw numbers to go off of. If I play much more with this before I get the rifle I want to use this brass with I will do a side by side accuracy after my next load testing.
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dangun
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Post by dangun on Feb 9, 2015 9:53:09 GMT -5
I see 2 nodes worth playing with:
140gr Nos BT with IMR 4895 37-38.8gr Lapua 308 (necked down) CCI BR4 primers my Rem 700 SPS Varmint with a 24" factory tube in .3 steps up the ladder:
37.9gr 10 shot string ave velocity was 2639fps with an SD of 14 and an ES of 18
38.5gr 10 shot string ave velocity was 2667fps with an SD of 12 and an ES of 19
With some fine tuning on charge or seating depth you might be able to get the SD and ES down into the single digits. I have had really good luck working with loads that produced Below 15 SD and below 20 on ES initially.
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Feb 9, 2015 18:14:43 GMT -5
I will do some more with this combo Dan if for no other reason than to see if I can find a better hunting load. I will work this up the ladder further to see if the improvements get better. I am also going to try a couple other bullets and powders. This might be a very fun summer while I wait on Hart to return my other rifle and I can run some 168 GK's and 162 A-Max bullets with 4350, Hunter (if I can find more) and 760/414.
I was pleasantly surprised by this from start to finish I shot these at a half sheet of plywood in front of my target board at 100 yards so I would like to do a side by side accuracy test at some point in the future. With this rifle and the most promising combos I try. I was a little leery about this experiment at first but I am thinking I am going to learn a lot. I will also come up with questions along way and seek input and suggestion from the crew here. |
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Feb 23, 2015 17:05:05 GMT -5
If weather holds like it is supposed to I will fire form my new Lapua LP brass this weekend so I can run a full cycle with 760 and 145gr Speer BTSP's the following week.
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bob
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Post by bob on Feb 23, 2015 19:39:52 GMT -5
Chuck: could you try BR2 primers instead of the 200s? Curious to see if that makes a difference in the ES.
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7mmmountaineer
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Post by 7mmmountaineer on Feb 23, 2015 20:13:17 GMT -5
Bob I am using 210M's in my LP brass. I have loads from 43-47 ready in my SP. Once I fire form my LP brass I will run the same cycle in that brass. If I see no excessive pressure signs I will run a cycle from 47-49 in .2 steps. It's a good thing I just ordered another 10 boxes of both the 145 and 160gr Speer BTSP's lol gonna be a fun spring and summer.
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Mar 14, 2015 10:42:10 GMT -5
As long as we don't get a gully washer here today I will run a cycle all Lapua brass both SP & LP. Powder will be W760 with 145gr Speer BTSP bullets cycle will be from 43-47gr in .3 steps up the ladder. Primers will be CCI BR4's and Federal 210M's. If I see no high pressure signs I will run another cycle from 47-49gr with the same combo in .2 steps. Looking for just some numbers data. If I get to shoot I will post my results.
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7mmmountaineer
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Time to face it I am a workaholic............
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Post by 7mmmountaineer on Mar 15, 2015 23:23:21 GMT -5
I did get to shoot part of a cycle today I got from 43-44.8gr of W760 with my Lapua LP & SP (Lapua resized 308) shot and really was under impressed with it. I used Fed 210M primers in my LP brass this time instead of CCI200's. Results to this point all 5 shot strings in the cycle are as follows:
Speer 145gr BTSP Win 760 and CCI BR4 43.0 2528fps SD 21 ES 30 43.3 2545fps SD 24 ES 37 43.6 2568fps SD 20 ES 26 43.6 2581fps SD 19 ES 26 44.2 2599fps SD 20 ES 35 44.5 2615fps SD 18 ES 24 44.8 2634fps SD 17 ES 21
Speer 145 BTSP Win 760 and Fed 210M 43.0 2539fps SD 20 ES 34 43.3 2557fps SD 19 ES 27 43.6 2575fps SD 17 ES 24 43.9 2592fps SD 16 ES 21 44.2 2610fps SD 15 ES 22 44.5 2627fps SD 14 ES 20 44.8 2645fps SD 13 ES 18
I am going to run this cycle out next weekend hopefully from 45.1-46.9 and see if it improves any. If it dose I will finish it out to the Speer max of 49.0 if I do not run into pressure issues. I am guessing the powder I chose this time has a roll in my ES and SD numbers as I had hoped they would track more along the lines of the IMR 4895 I started out with. I figured 70 rounds was about the max I wanted to shoot today and I hate going much longer with out cleaning my rifle. |
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bob
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Post by bob on Mar 15, 2015 23:41:37 GMT -5
What was the temperature like Chuck? I don't really see much difference between the two which is in itself interesting. Thanks for the effort, look foward to the finish!
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7mmmountaineer
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Post by 7mmmountaineer on Mar 17, 2015 15:29:07 GMT -5
Bob it was in the low 50's I didn't record all the weather conditions I also shot at a different location about 2000ft close to see level than when I shoot at home. I don't know if that affected my results or not but it is a factor to consider but it could have. I will finish the cycle at home and see if their is any difference in my SD and ES numbers. I know being closer to sea level can muddy up results but I was really under impressed.
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bob
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Post by bob on Mar 17, 2015 16:55:24 GMT -5
The reason for asking about the temperature was H414/ W760 are said to be temperature sensitive especially to cold, which is where they recommend magnum primers. A couple thosand feet should not make all that much difference, at least no more than a change in atmospheric pressure. Any difference should be negated by your running the balance of the test with both primers at the new location and temperature as your comparing load for load not one charge weight against a different weight. So far it is interesting to note little difference. What if you took a few of each, 210M and BRC4, primed cartridges and put them in a refrigerator to simulate cold weather then shot them.( After removing them from the refrigerator )  |
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7mmmountaineer
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Post by 7mmmountaineer on Aug 4, 2015 20:08:48 GMT -5
Getting geared up for a full blown run at this little experiment. My rifle from Hart is due back 9/1 just in time for a 3 day weekend. I have 30 break in loads ready a nice Vortex Diamond HP 4x16x42 ready to mount. So I will breaking in and zero starting 9/2 with 150gr SIE MK's and IMR4350 then switch over to 168 SIE MK's and H414 for the first run at this. The LP brass will be Lapua like the SP brass. The large primers will be FED 210M and the small primers will be CCI BR4. I can not wait to see how this turns out.
I will also try this experiment with one of IMR's new powders when I get the chance 4551. |
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My daughter came from Missouri, my son and grand son, my wife and I had a nice dinner of grilled "porter house" pork chops, corn on the cobb, my son, G'son and I share 10/5. G'son is 4 minutes early though @ 10/4.
Pooh I hope you find to right house . 
