20x47 Lapua - help needed

[trappst]

Looking for some help from you wildcatters out there. Dcloco,I know we've talked via PM a little bit about this so please chime in.

Re-chambered 204 Ruger 1:12 twist barrel. Got some data via quickload from a member over at Saubier...it's way off (using 20 Satan data). Lapua brass reformed and necks turned to .014". Fed GM205M primers and Nosler 40g bullets seated at the lands. For powder, I started with Varget....first time, I was way over pressure with primers cratering something terrible.

Today, I shot a little starting a full 2g lower than where I was previously. Still showing too much pressure, not as bad, but still too much. I set up the chrono today and was only getting 3,900 fps at 31g. Went to 31.5 and pressure got worse but the shot was showing a lower velocity than the previous 31g load. The shot kinda sounded weird too.....almost like the powder wasn't burning fully.

Can anyone give me a direction to go here? The funny sounding shot makes me think either a powder or primer switch is order. If I stick with Varget, do you think a CCI 450 could make a huge change in pressure?

Please help!

[outlawkyote]

hhhmmm
Thats weird, my 204 apache is getting 4100-4200fps while using 30gr of varget and 40 gr bullets. I cant fit anymore powder in the brass though. What twist are you running? You might also back off another 2 gr of powder and try magnum primers. Or is the cci 450 a magnum primer?
Mine likes rel15 better also, Varget was too dirty. Might also try some H380 and BLC2 also. Apache claims rel17 was a very accurate powder in it too.

[trappst]

barrel is a factory 1:12 twist that was re-chambered

the cci450 is a mag primer. I haven't tried the mag primers yet though....been using Federal match up till now.

I just can't believe I'm over pressure and only getting 3,900 fps

[groupshooter22]

Try the cci primer. From what I understand the federals dont do high pressure good. CCI is supposed to hold up better.

[Apache]

Overbore cartridges generally like slower burning powders....I would try RL17 for sure also H4350. Might be a little too slow, but I would try that burn rate for sure.

If it ends up that you are able to fill the case and not get any pressure signs then go with a little faster burn rate. If it tops out with pressure signs and the case still isn't full.....go with an even slower burn rate. Those are the general rules I use when developing loads.......for what it's worth.

You're looking for 98% to 100% case fill with the proper pressure signs (as long as it's ACCURATE)

[trappst]

Good 'ole Apache! I knew you couldn't resist something different ;)

I just happen to have a new unopened 1lb container of R-17 sitting here. My supply of H4350 is being used up fast with the 25-06 and 6mm Rem......

Any ideas on where to start charge wise with the R-17?

I think I still may try the cci 450 and Varget just to see what it does (will reduce farther though)

[Apache]

Good 'ole Apache! I knew you couldn't resist something different ;)

I just happen to have a new unopened 1lb container of R-17 sitting here. My supply of H4350 is being used up fast with the 25-06 and 6mm Rem......

Any ideas on where to start charge wise with the R-17?

I think I still may try the cci 450 and Varget just to see what it does (will reduce farther though)


;D

Again, GENERALLY SPEAKING, ;) You can look at other cartridges with similar case capacity and close to caliber (20/250 would be ideal, 22-250, 22x47L....6x47L, 6/250) and get an idea of starting loads. Of coarse you want to reduce charges due to bore reduction....the 6mm calibers listed are getting a little too far in caliber from 20 caliber for comparison but should still work in this particular instance.

If it were me, I would start with 34grns and work from there.....taking the proper precautions with the first shot of coarse. Most are loading somewhere around 40grns or so of RL17 in the 6X47L at top loads.

BTW.....if you have access to them, use mag primers. I have grown partial to the Russian (Wolf) primers lately....was forced into using them by the primer shortage....now I'm glad I did. They stand up to high pressure much better than most others.

[dcloco]

I use CCI 450 primers almost exclusively, in small rifle cases, for no other reason, than thicker primer cups. I do try to use powders that are the least temp sensitive, because I may be shooting in 20F to 110F temps. Which, is asking a lot of the powder.

When working up loads while shooting over a chronograph, the speed rises, rises, rises, plateaus or falls a bit, then plateaus or increases some. This is usually indicating you are at the max velocity for the powder/primer/bullet/temperature.

I think you are using the wrong powder. When wildcatting, I tend to try some of the powders listed in reloading manuals if the bullet weight are within 10-15 grains. Here is hodgdon's data (varget is not listed, yes, it is close in the burn rate chart, but not listed):

Data for 6x47 (I know.... 0.243 bullet....)

60 GR. SIE HP Hodgdon BL-C(2) .243" 2.400" 28.5 2963 34,200 CUP 30.5 3233 45,300 CUP
60 GR. SIE HP Hodgdon H335 .243" 2.400" 28.0 2911 33,600 CUP 30.0 3202 45,100 CUP
60 GR. SIE HP Hodgdon H4895 .243" 2.400" 26.0 2919 35,600 CUP 28.5 3098 43,100 CUP
60 GR. SIE HP Hodgdon H322 .243" 2.400" 26.0 3040 38,100 CUP 28.0 3222 44,500 CUP
60 GR. SIE HP Hodgdon H4198 .243" 2.400" 22.0 2895 35,400 CUP 24.0 3170 49,800 CUP
70 GR. HDY SP Hodgdon BL-C(2) .243" 2.445" 28.0 2902 39,300 CUP 30.0 3050 48,000 CUP
70 GR. HDY SP Hodgdon H335 .243" 2.445" 27.5 2884 37,900 CUP 29.5 3029 47,200 CUP
70 GR. HDY SP Hodgdon H4895 .243" 2.445" 26.0 2745 37,600 CUP 28.0 2915 44,700 CUP
70 GR. HDY SP Hodgdon H322 .243" 2.445" 26.0 2935 43,000 CUP 28.0 3116 49,800 CUP
70 GR. HDY SP Hodgdon H4198 .243" 2.445" 21.0 2726 39,300 CUP 23.0 2944 49,400 CUP
75 GR. SPR HP Hodgdon BL-C(2) .243" 2.445" 27.5 2792 37,500 CUP 29.5 2997 47,400 CUP
75 GR. SPR HP Hodgdon H335 .243" 2.445" 27.0 2744 37,100 CUP 29.0 2953 46,900 CUP
75 GR. SPR HP Hodgdon H4895 .243" 2.445" 25.5 2709 38,200 CUP 27.5 2911 47,500 CUP
75 GR. SPR HP Hodgdon H322 .243" 2.445" 24.0 2698 40,300 CUP 26.0 2958 48,400 CUP
75 GR. SPR HP Hodgdon H4198 .243" 2.445" 20.5 2664 41,500 CUP 22.5 2852 48,900 CUP
80 GR. SPR SP Hodgdon BL-C(2) .243" 2.440" 27.0 2725 40,400 CUP 29.0 2935 48,500 CUP
80 GR. SPR SP Hodgdon H335 .243" 2.440" 26.5 2696 39,900 CUP 28.5 2909 48,200 CUP
80 GR. SPR SP Hodgdon H4895 .243" 2.440" 25.0 2622 40,400 CUP 27.0 2860 49,800 CUP
80 GR. SPR SP Hodgdon H322 .243" 2.440" 23.5 2604 41,400 CUP 25.5 2808 48,000 CUP
80 GR. SPR SP Hodgdon H4198 .243" 2.440" 20.0 2527 39,800 CUP 22.0 2700 46,900 CUP
85 GR. SPR SP Hodgdon BL-C(2) .243" 2.440" 26.0 2636 43,100 CUP 28.0 2847 50,300 CUP
85 GR. SPR SP Hodgdon H335 .243" 2.440" 25.5 2601 42,200 CUP 27.5 2797 48,900 CUP
85 GR. SPR SP Hodgdon H4895 .243" 2.440" 24.0 2483 39,800 CUP 26.0 2712 49,400 CUP
85 GR. SPR SP Hodgdon H322 .243" 2.440" 23.0 2514 40,800 CUP 25.0 2713 48,000 CUP
85 GR. SPR SP Hodgdon H4198 .243" 2.440" 19.5 2400 37,100 CUP 21.5 2571 46,900 CUP




Here is the data for the 20 PPC from 6mmBr website (nobody using Varget either)

20 PPC LOAD MAP
Bullet GR Maker Powder Charge Primer Case Velocity BarrelTwist Comments
32 Hornady V-Max H322 27.6 Rem 7½ Lapua 4000 Lilja 1:12 WarrenB Form Load
32 Hornady V-Max H4198 25.1 CCI BR4 Lapua 4222 PacNor 1:12 A. Boyechko Load
39 Sierra BlitzKing H322 26.0 Rem 7½ Lapua 3700 Lilja 1:12 WarrenB Load
39 Sierra BlitzKing VV N540 28.8 CCI BR4 SAKO 4064 PacNor 1:12 D.Moore, Low 2s
40 Hornady V-Max VV N135 27.8 Fed 205m Lapua 3950 Lilja 1:9 SnakeEye Load
50 Berger LTB VV N135 26.0 CCI 450 Lapua 3615 Lilja 1:9 SnakeEye Load
50 Berger LTB Varget 27.3 CCI 450 Lapua 3595 Lilja 1:9 SnakeEye Load


Believe you might be using too slow of a powder.

Why are you starting with the bullet on the lands? Unless testing shows a bullet on the lands DOES improve accuracy, there really is not a good reason to do this. Not necessarily a bad thing to do, but every caliber and barrel and bullet is different. Even Berger has backed off of saying their bullets should be seated to or into the lands. I base this on both of my 204 barrels actually being more accurate 0.045 to 0.050 OFF the lands. This might cure some pressure problems as well.

[358Hammer]

+1 with Dcloco

I have never used a mag primer on a case that holds less than a 8 mag charge of slow burning powder. With the charge of slow to caliber powder having no place to go when the bullet is seated against the lands. Its naturally going to build up pressure causing bolt back thrust first, then propulsion down the barrel. I kind of had this issue today in a very large capacity case.

Yesterday load x using 210 primer shot and ejected perfectly(incredible group). Today I substituted only the primer with Fed 215's. Bolt lift was extreme and I had to drive the case from the chamber.

Neal

[trappst]

Thanks fellas!

Loading at the lands only to make adjustment easier....start at the lands, and I only got one way to go. The only round I jam bullets for is my 20BR. After I find a charge, all I gots to do is turn the dial on the comp. seater in.

My main thing here is the pressure I'm seeing vs. the velocity I'm able to achieve. I know backing off the lands will decrease pressure but at this point, I serious doubt seating depth alone will lower pressure enough.

No real reason for the Varget choice...had quite a bit that wasn't being used. Case capacity is similar to the 22-250 so I thought it might be okay. Guess not eh? :P

Gosh, should I just fall back on the tried and true, use it in everything H4895?

[dcloco]

Gosh, should I just fall back on the tried and true, use it in everything H4895?



I know a gent that won't own a rifle caliber if it does not shoot Ball C or H4895. His reason is basic....keeps things simple and accurate.

It might just be me....but I have never got the accuracy out of Varget that everybody else has. I don't know why. I almost wore out a couple barrels in different calibers trying Varget. ARGH! :)

Of interest....I ALWAYS start 0.020" off the lands (or max mag length if 0.020" off the lands or more at mag length). The 204 is the only caliber that I have loaded for that LIKES being further off the land. Almost stumped me....serious!

[dcloco]

trappst - see here....

http://savageshooters.com/SavageForum/index.php/topic,26737.0.html

[trappst]

Can of BL-C(2) was sitting on the shelf saying: "c'mon coach, put me in! I won't let ya down coach, put me in!"

Soooo, loaded up a few with BL-C(2). If that doesn't give me what I want, I'm headed the other direction with R-17.

[trappst]

Welp, it's off to R-17 and cci 450's for me.

BL-C(2) was terrible.......low velocity and hang fires for the whole string. Also showing ejector marks at only 3,700 fps.

[Apache]

If you get a full case and no signs of pressure and still not getting the velocity you expect, go to a little faster powder. RL17 has been rated around H4350 burn rates by most poeple.....although its true burn rate is a little faster but due to the power curve it has, it rates as it does.

I have an OLD powder program called "Suggest a Load" and it suggests H380 or similar and predicts a MAX charge of 40.8grns with a velocity of 4239 with a 40grn bullet if you want to try something like that. H380 is slightly faster than H4350.....

Let me know how it does........