Reloader 26/Short Barrels

[AZ82New]

Until today, I never put any stock into there being better powders for short barrels. I believed that if a listed powder was the fastest when tested in a 24 inch barrel, it would still be the quickest in a shorter tube compared to other powders.

This is not true.

I have been struggling to get velocity out of a 20 inch 300 WSM I just built. Rather than ramble, I'll give you the velocity numbers.

69 grains of reloader 26, 190 Speer Impact, is getting me 2,820 fps.

The load manual says 3,004 fps with a 24 inch barrel. I knew I would lose some velocity but not 184 fps!

So after 60 rounds of this, I finally just try a faster powder. 66.5 grains of Staball 6.5 got me 2,910 fps and less case expansion measured by a micrometer.

Hodgdons load manual says that 66.3 grains of Staball 6.5 should get me to 2,960 fps. in a 24 inch barrel with 61k psi.

So I pushed it a little past max due to a little bit of head room on the pressure and the cases are doing fine. The velocity loss from a 24 to a 20 inch tube isn't even worth mentioning.

Unless anyone with some experience here can give me a better explanation, I'm going with the faster burn rate was what made the difference.

 

[outdoorguyBP]

Shorter barrel, less time to burn before the bullet leaves the barrel, faster powder for the charge to burn off. Longer barrel, more time, slower burn. That has been my thought process but not very scientific

 

[AZ82New]

Shorter barrel, less time to burn before the bullet leaves the barrel, faster powder for the charge to burn off. Longer barrel, more time, slower burn. That has been my thought process but not very scientific

Makes sense.

What I have read or heard is that the actual burning of the powder is done relatively quickly with either a fast or slow powder, it's the expanding gasses, post burn, are what is accelerating the bullet further.

This burn rate in shorter barrels is a myth.

I don't believe that anymore. The faster burning powder was clearly better in my 20 inch barrel. What I could do is fire both loads in my 24.3 inch barreled 300 WSM and compare those. The reloader 26 should be slightly faster or at least comparable.

I'll try that and report back.

 

[outdoorguyBP]

Yup. I plan on trying H-1000 in a 22" 7PRC soon along with some faster burning IMR7828 and H4831 and see how it goes

 

[AZ82New]

Yup. I plan on trying H-1000 in a 22" 7PRC soon along with some faster burning IMR7828 and H4831 and see how it goes

Yeah man, let me know. I'm also working on a 23 inch 7prc I just got from the smith.

Factory 175 ELDX is going 2,845 fps out of it. The ES is only 20 fps. Looks like Hornady did a good job on the quality of the ammo for sure. However, that's no better than the 2,850 fps I'm getting from a 22 inch 280 ai with the SAME bullet and H1000.

 

[adk hunter]

Yeah man, let me know. I'm also working on a 23 inch 7prc I just got from the smith.

Factory 175 ELDX is going 2,845 fps out of it. The ES is only 20 fps. Looks like Hornady did a good job on the quality of the ammo for sure. However, that's no better than the 2,850 fps I'm getting from a 22 inch 280 ai with the SAME bullet and H1000.

This is what I've been wondering or guessing exactly. May be apples and oranges pressure wise, don't care. Only thing "better" is big red making ammo and not gouging too bad. If someone (NOSLER) would get off their backside and sell a 150 long-range accubond load for $48 they could build a new plant with the $$$.

Now all you new 7PRC guys go hot rod the heck out of it and have a blast!!

 

[Tiny Tim]

Hodgdons load manual says that 66.3 grains of Staball 6.5 should get me to 2,960 fps. in a 24 inch barrel with 61k psi.

So I pushed it a little past max due to a little bit of head room on the pressure and the cases are doing fine. The velocity loss from a 24 to a 20 inch tube isn't even worth mementioning.

My only caution would be that Staball 6.5 pressures out rapidly, often going from fine to dang in a small incremental increase in charge weight.

Glad you found something that closes the gap. Near 200 fps loss in 4" is crazy. Usually takes extremely overbore cartridges to see those kinds of losses.

 

[Gstew1930]

The velocity in data is usually way off in my experience. i wouldn't take that as a RL26 problem

 

[lancetkenyon]

One test result doesn't necessarily mean proof.

20" .260AI w. 140 Hyb.

46.6gr H4350 (max-slight ejector mark, slight bolt lift), 140 Hyb @ 2951fps
46.2gr H4350 (max safe load), 140 Hyb @ 2911fps
50.0gr RL26 (max due to full case-no pressure), 140 Hyb @ 2997fps

I have a 24" .260AI as well. There is exactly 100fps difference with the exact same loads fired in each. 44.8gr H4350 is my steel load in the 24", and a 140 Hyb @ 2938 (24") vs 2838 (20"). 46.3gr is my hunting load @ 3028fps.

 

[VinceMule]

Lance's loads mimic many that shoot the 260 AI. Lance, what brand of brass have found that works well for you with these loads?

 

[Will.284]

Yup. I plan on trying H-1000 in a 22" 7PRC soon along with some faster burning IMR7828 and H4831 and see how it goes

Just yesterday 7prc /175 grain hornandy eld-x and 68.8 grains h-1000 5 shot group 2974.2 fps with 8.8 sd Hornandy brass3rd loading fed lrmp's out of a 22 inch Oregon Mountain rifle barrel on a 116 stainless savage!!!! F.O.D !! That's hard to beat

 

[bultinkle]

Rl26 shot really well in my 21" 300prc. Got 2850 with a 215 with book max, but with berger data went past that

 

[VinceMule]

Love to see the target! Will

 

[bultinkle]

This is what I've been wondering or guessing exactly. May be apples and oranges pressure wise, don't care. Only thing "better" is big red making ammo and not gouging too bad. If someone (NOSLER) would get off their backside and sell a 150 long-range accubond load for $48 they could build a new plant with the $$$.

Now all you new 7PRC guys go hot rod the heck out of it and have a blast!!

Nosler won't even make enough partitions to feed the market and they've been making that for 6 decades.

Hurry up and wait if you want nosler to make bullets