what powder to use in short barrel?

[bigt73]

if you had a short barrel in .204 18" long. what powder would you chose to use to get the fps up and why?
so far i have come up with : vit n130, h 4198, re-10x..


tony

[Fred_C_Dobbs]

I don't have any experience with an 18" .204 but you're not getting a lotta help here, so I thought I'd chime in.

Pmax occurs about two inches down the barrel so I don't think a shorter rifle barrel of itself makes a powder change necessary compared to a "normal" length barrel. Nonetheless, you aroused my curiosity so I fired up QuickLoad and plugged in a number of different powders to see how they'd stack up. This was done using all QL's default dimensions, capacities, burn rates, etc, except for the 32-gr SBK and an 18" barrel, and using the manufacturer's max published charge weight:

VV 130 (25.0-gr): 3624 fps
VV 135 (27.0-gr): 3574 fps
VV 530 (27.0-gr): 3700 fps
BL-C(2) (30.7-gr): 3845 fps
8028 XBR (29.0-gr): 3906 fps
Benchmark (28.0-gr): 3832 fps
RL-10x (26.3-gr): 3920 fps
IMR 4895 (29.0-gr): 3774 fps
H4895 (29.0-gr): 3877 fps

I should note that the default "burn rate factor" in the QuickLoad database always ALWAYS requires tweaking by the user, based on chronograph data, to be truly accurate.

[wirelessguy2005]

Give Ramshot Xterminator a try.

[bigt73]

I don't have any experience with an 18" .204 but you're not getting a lotta help here, so I thought I'd chime in.

Pmax occurs about two inches down the barrel so I don't think a shorter rifle barrel of itself makes a powder change necessary compared to a "normal" length barrel. Nonetheless, you aroused my curiosity so I fired up QuickLoad and plugged in a number of different powders to see how they'd stack up. This was done using all QL's default dimensions, capacities, burn rates, etc, except for the 32-gr SBK and an 18" barrel, and using the manufacturer's max published charge weight:

VV 130 (25.0-gr): 3624 fps
VV 135 (27.0-gr): 3574 fps
VV 530 (27.0-gr): 3700 fps
BL-C(2) (30.7-gr): 3845 fps
8028 XBR (29.0-gr): 3906 fps
Benchmark (28.0-gr): 3832 fps
RL-10x (26.3-gr): 3920 fps
IMR 4895 (29.0-gr): 3774 fps
H4895 (29.0-gr): 3877 fps

I should note that the default "burn rate factor" in the QuickLoad database always ALWAYS requires tweaking by the user, based on chronograph data, to be truly accurate.

thank you so much for that, i will be using 39sbk the full volume of the case is 33.7 grains thats with water, i have re10x and i am hoping that this should get me too 3650, the h335 powder only gave me 3270 @26.2 grs after that i get pressure signs..

again thanks

tony

[Fred_C_Dobbs]

What pressure signs were you seeing? The firing pin hole in the bolt face of many .204 rifles has sloppy tolerances and produces an early onset of cratering. I have a Savage .204 that craters the primers on every factory load I've shot in it.

Using your case capacity and the 39-gr SBK, I get 3264 fps, so QL's default BRF for H335 is remarkably close to your range data. But that was at 60°F, being as you're in the UK ). If I go to 26.8-gr (Hodgdon's max for a 40-gr pill), I get 3338 fps and about another 2500 psi.

Alliant's max RL-10x charge weight with the 39-gr SBK is only predicted to get you 3700 fps with a full length barrel so 3650 might be a bit of an ask with the 18" barrel. Using your case capacity, 60°F and 18", QL predicts 3484 fps from the RL-10x. Just for giggles, I ran the MV up to 3600 fps with 10x, XBR and BL-C(2). All three needed about 5000 psi over SAAMI max pressure to get there but the BL-C(2) was lowest predicted pressure of the three by a slight margin.

[Fred_C_Dobbs]

I tried the max published load of X-terminator for a 40-gr V-max with the 39-gr SBK and got 3338 fps. But calculated Pmax was 8000 psi under SAAMI max px. I suspect QL doesn't have a very accurate burn rate factor for the X-terminator.

[rioslu]

Hello,

I run a 20" REM700SPS. I too was concerned with velocities when i decided to cut down my barrel. I found this site http://www.bullberry.com/204Rugerdata.html and went based on the tests. FYI, Im loading 39gr Sierra BK on top of 24.8 R10X and Federal 205M primers. My velocities are as follow,
1. 3510
2. 3509
3. 3512
4. 3532
5. 3516
ES 23.0
SD 9.3
Apprx Elev 2000ft and Outside Temp Apprx. 68f

and this is how it groups,


at 200yds with called flyer,


Hope my info helps.
Luis

[bigt73]

What pressure signs were you seeing? The firing pin hole in the bolt face of many .204 rifles has sloppy tolerances and produces an early onset of cratering. I have a Savage .204 that craters the primers on every factory load I've shot in it.

Using your case capacity and the 39-gr SBK, I get 3264 fps, so QL's default BRF for H335 is remarkably close to your range data. But that was at 60°F, being as you're in the UK ). If I go to 26.8-gr (Hodgdon's max for a 40-gr pill), I get 3338 fps and about another 2500 psi.

Alliant's max RL-10x charge weight with the 39-gr SBK is only predicted to get you 3700 fps with a full length barrel so 3650 might be a bit of an ask with the 18" barrel. Using your case capacity, 60°F and 18", QL predicts 3484 fps from the RL-10x. Just for giggles, I ran the MV up to 3600 fps with 10x, XBR and BL-C(2). All three needed about 5000 psi over SAAMI max pressure to get there but the BL-C(2) was lowest predicted pressure of the three by a slight margin.

the pressure signs where cratoring @26.5 26.8 flattened the primer and when pushed to 27.5 blew a hole in it
so the 26.2 was the highest and safest load
i rang sierra and they said there top load of re10x was 25.1grs and was also the most accurate one.
ive loaded some rounds up starting at 23.0grs all the way up to 26.0grs and will see first where they start to show pressusre, then make some 5 different loads up, up to that max and see which is most accurate.
i will start saving for a rebarrel i, got a quote for £660 pounds for a 1:11 pacnor i would have that cut too 22".

you mentioned that the howas have a sloppy firing pin, can that problem be sorted?
thanks for all your help..

tony

[Fred_C_Dobbs]

It isn't really a problem unless it produces piercing. Unfortunately, you're already there.

You need a machinist/gunsmith who can "bush" the firing pin hole to reduce the tolerance.

Is it a bolt gun? With an 18" barrel, I took it for an AR.

[bigt73]

It isn't really a problem unless it produces piercing. Unfortunately, you're already there.

You need a machinist/gunsmith who can "bush" the firing pin hole to reduce the tolerance.

Is it a bolt gun? With an 18" barrel, I took it for an AR.

sorry forgot to say its a howa so, yep hunting rifle not ar.
does that make a difference?

[bigt73]

fred c Dobbs, what is the psi of that load i used of h355 @26.2grs with 39grs sbk.
i was just wondering if that psi would be the mark for all the powders in my chamber, would they all be on the cusp at the same psi?
i hope this makes sense, as i want to know what load of re10-x in grs would produce the same psi..?
any help
tony

[Fred_C_Dobbs]

bigt73, one of the quirks of my (very old) copy of QuickLoad is that the pressure predictions sometimes are wildly off the mark. Strangely, it doesn't seem to affect the accuracy of the MV predictions. I reckon pressure and velocity must use separate and independent logic circuits. I don't generally take stock in anything it says until I've worked up range data to vet it.

Anyway, my pressure predictions for H335 look highly suspect. Using your case capacity, if I enter Hodgdon's max load with a 40-gr bullet (but using the 39-gr SBK), I get a tad less than 52K psi. Hodgdon predicts 56.7K. I get 48.4K from 26.2, and that's at 70°F. I would not try to hang my hat on those numbers.

[bigt73]

so the max pressure will be the same across, all powders in that chamber although, the weight of powder will change from one powder to another..
is that right?
if so i could use that as a mark as to where my max load will be with other loads, ie re10x?

tony

[Mark C]

Hi Tony,

Not exactly what you asked but my .204 had a 26" barrel which I had reduced to 23" re-crowned & threaded for a can, accuacy not affected at all just the point of impact changed but a quick zero session sorted that out.

I load 39gr SBK, 25.2 gr RE-10x @2.307" COAL with winchester brass & CCI BR-4 primers, over the chrono it shoots 3714 fps (average of 10 shot string), five shot groups at 100yds of 0.285"

The gunsmith that did the work was great & explained every thing in detail regarding how velocity versus accuacy would be affected after the barrel was shortened, all I can say is that it tranformed the rifle a lot easier to point & handle.

regards Mark

[bigt73]

Hi Tony,

Not exactly what you asked but my .204 had a 26" barrel which I had reduced to 23" re-crowned & threaded for a can, accuacy not affected at all just the point of impact changed but a quick zero session sorted that out.

I load 39gr SBK, 25.2 gr RE-10x @2.307" COAL with winchester brass & CCI BR-4 primers, over the chrono it shoots 3714 fps (average of 10 shot string), five shot groups at 100yds of 0.285"

The gunsmith that did the work was great & explained every thing in detail regarding how velocity versus accuacy would be affected after the barrel was shortened, all I can say is that it tranformed the rifle a lot easier to point & handle.

regards Mark

thats ok but, that bloody rfd cut mine to 18" told me it was 22" so now i am stuck with this rifle and, the reason i went with the .204 was for the fps and its inherrent accuracy, now every thing is just so frustrating, i shoot the 30sbk and because of the lack of fps i dont get the the benifit of it high bc and if i decide to shoot out further then the drops will really show, and at the min i am trying to work out what load in the psi reagion would be the same as the one i am using, but in a differnt powder as this would save me time and at least i would get to know what fps to expect....

tony