Someone please help me understand these numbers!

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rebel
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Re: Someone please help me understand these numbers!

Post by rebel » Sun Jan 19, 2020 4:28 pm

dellet wrote:
Sun Jan 19, 2020 3:23 pm
Back to the actual question.

Drop 19 grains in a fired case, rest a bullet on the powder and measure.

What’s the length?
This and to add to bang's theory-and I don't use the TNT - he is closer to the lands, thus more pressure. I doubt up in there as it is a short, fat bullet.
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McAda441
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Re: Someone please help me understand these numbers!

Post by McAda441 » Sun Jan 19, 2020 8:00 pm

2.084" has bullet resting on the powder

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Re: Someone please help me understand these numbers!

Post by McAda441 » Sun Jan 19, 2020 8:05 pm

I thought it odd as well that speer hasn't published any load data on this pill. I'm just gonna keep fiddling with it and see how fast I can get it and how close to 20gr it'll go

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Re: Someone please help me understand these numbers!

Post by TRshootem » Sun Jan 19, 2020 9:30 pm

With 18.6 gr of H110, my OAL is 2.060 and accuracy is very good in bolt and AR. Not chasing velocity but rather accuracy.

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Re: Someone please help me understand these numbers!

Post by dellet » Sun Jan 19, 2020 10:22 pm

McAda441 wrote:
Sun Jan 19, 2020 9:57 am
Got a good deal on a bunch of speer 125gr TNT rounds and so I've been working on some loads. Went to the range yesterday and had something very weird happen once I got into the hotter loads.
H110 powder, WSR primers, and once fired frontier brass for all rounds w/o crimp. Shot out of an 8.5" noveske match barrel 1:7 twist. Velocity recorded with my LabRadar chronograph
10x 17.5gr 2.060" coal -- 1864 avg fps sd 26 1.5" spread
10x 18gr 2.075" coal -- 1924 avg fps sd 29 1.2" spread
10x 18.2gr 2.075" coal -- 1931avg fps sd 18 0.8" spread
10x 18.5gr 2.075" coal -- 1944avg fps sd 22 0.75" spread
10x 18.8gr 2.075" coal -- 1978avg fps sd 14 1.2" spread
10x 18.8gr 2.100" coal -- 2054avg fps sd 25 0.6" spread
10x 19gr 2.100" coal -- 2098avg fps sd 19 0.4" spread
Zero pressure signs in any cases, obviously published load data hasn't properly tested this projectile.
Anyways, i have two questions. First, does anybody have any explanation as to why I had such a large increase in velocity with the slightly longer 18.8gr rounds?
Second, doesn't 2100fps seem pretty damn high out of an 8.5" barrel? Avg was 2098 but I had two rounds at 2112fps. Maybe someone with quick load can crunch some numbers for me but that just seems like a helluva lot of pressure. I'd like to see if I could work up to 20gr of powder but these might be close to or over max pressure. Again, no pressure signs on the case but the chrony tells a different story.
Hopefully that was a fired case with 19 grains, either way this is pretty typical of H110. You could verify this, but I’ll probably be close. Around 18.2 you had the bullet very close to the powder, maybe even touching, the velocity flattened out. Basically the charge lost efficiency. 18.8 @ 2.075” a bit of compression, it got harder for the primer to set off the dense charge. When you moved the bullet out to 2.100 you got back to a sweet spot for density. This powder seems to excel with 98-100% load density.

My rule of thumb and where I start my loads, is measure the charge as I asked you to do with 19 grains. Then add .010” to the length of 2.086” that you measured 2.095”. Depending on data available I might have started at 18.5. I adjust my powder charges and seated depth together, .1 grains +/- is .010”-/+ bullet movement. That would have been 18.5 grains at 2.045” note Trshootem’s load of [email protected] 2.060”.

This is a very predictable powder.

The only problem you may have going to 20 grains is running out of neck to hold the bullet in. If you keep the bullet just off the powder, you may not see pressure sign before running out of case. The flip side of that is you can get away with slight compression with max loads. Then you add .2 grains and it spikes enough to blow a primer.

I don’t know Winchester small rifle primers well enough, if you change to a magnum, start all over. Your velocities do seem high by about 75-100 fps. If your not seeing pressure signs I wouldn’t worry. Try and verify with a second chrono or pay attention to drops, they may be excessive if that speed in not correct.

I do have a 12” barrel that is faster than all my 16” barrels, it happens.

Keep tons of data and look for patterns.load density is often over looked and different powders have different sweet spots. Once you find it, it cuts load development time significantly.
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Re: Someone please help me understand these numbers!

Post by McAda441 » Mon Jan 20, 2020 10:02 pm

TRshootem wrote:
Sun Jan 19, 2020 9:30 pm
With 18.6 gr of H110, my OAL is 2.060 and accuracy is very good in bolt and AR. Not chasing velocity but rather accuracy.
Yeah I had good accuracy around the 18.6gr range it got better as the charge increased though. Also once I stopped compressing the powder it seemed to give me higher speeds. In my experience things tend to be a little more accurate the faster they are just out of these short barrels.

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Re: Someone please help me understand these numbers!

Post by McAda441 » Mon Jan 20, 2020 10:09 pm

dellet wrote:
Sun Jan 19, 2020 10:22 pm
McAda441 wrote:
Sun Jan 19, 2020 9:57 am
Got a good deal on a bunch of speer 125gr TNT rounds and so I've been working on some loads. Went to the range yesterday and had something very weird happen once I got into the hotter loads.
H110 powder, WSR primers, and once fired frontier brass for all rounds w/o crimp. Shot out of an 8.5" noveske match barrel 1:7 twist. Velocity recorded with my LabRadar chronograph
10x 17.5gr 2.060" coal -- 1864 avg fps sd 26 1.5" spread
10x 18gr 2.075" coal -- 1924 avg fps sd 29 1.2" spread
10x 18.2gr 2.075" coal -- 1931avg fps sd 18 0.8" spread
10x 18.5gr 2.075" coal -- 1944avg fps sd 22 0.75" spread
10x 18.8gr 2.075" coal -- 1978avg fps sd 14 1.2" spread
10x 18.8gr 2.100" coal -- 2054avg fps sd 25 0.6" spread
10x 19gr 2.100" coal -- 2098avg fps sd 19 0.4" spread
Zero pressure signs in any cases, obviously published load data hasn't properly tested this projectile.
Anyways, i have two questions. First, does anybody have any explanation as to why I had such a large increase in velocity with the slightly longer 18.8gr rounds?
Second, doesn't 2100fps seem pretty damn high out of an 8.5" barrel? Avg was 2098 but I had two rounds at 2112fps. Maybe someone with quick load can crunch some numbers for me but that just seems like a helluva lot of pressure. I'd like to see if I could work up to 20gr of powder but these might be close to or over max pressure. Again, no pressure signs on the case but the chrony tells a different story.
Hopefully that was a fired case with 19 grains, either way this is pretty typical of H110. You could verify this, but I’ll probably be close. Around 18.2 you had the bullet very close to the powder, maybe even touching, the velocity flattened out. Basically the charge lost efficiency. 18.8 @ 2.075” a bit of compression, it got harder for the primer to set off the dense charge. When you moved the bullet out to 2.100 you got back to a sweet spot for density. This powder seems to excel with 98-100% load density.

My rule of thumb and where I start my loads, is measure the charge as I asked you to do with 19 grains. Then add .010” to the length of 2.086” that you measured 2.095”. Depending on data available I might have started at 18.5. I adjust my powder charges and seated depth together, .1 grains +/- is .010”-/+ bullet movement. That would have been 18.5 grains at 2.045” note Trshootem’s load of [email protected] 2.060”.

This is a very predictable powder.

The only problem you may have going to 20 grains is running out of neck to hold the bullet in. If you keep the bullet just off the powder, you may not see pressure sign before running out of case. The flip side of that is you can get away with slight compression with max loads. Then you add .2 grains and it spikes enough to blow a primer.

I don’t know Winchester small rifle primers well enough, if you change to a magnum, start all over. Your velocities do seem high by about 75-100 fps. If your not seeing pressure signs I wouldn’t worry. Try and verify with a second chrono or pay attention to drops, they may be excessive if that speed in not correct.

I do have a 12” barrel that is faster than all my 16” barrels, it happens.

Keep tons of data and look for patterns.load density is often over looked and different powders have different sweet spots. Once you find it, it cuts load development time significantly.
Hey thanks for all the insight. I've had no issued with the WSR primers with 1680 and subsonic loads, or the H110 going up to 19gr. If they start giving me issues having this much powder in case I'll start from scratch with the cci 450s. For now I've got another 100 of these ranging from 19.1-20gr of H110. I'll find out what the real working max is for these.

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Re: Someone please help me understand these numbers!

Post by cdl » Tue Jan 21, 2020 5:37 pm

Might be of interest...

18gr - H-110 behind the Speer 125gr SST shot almost as accurate, and similar to my 125 SST's w/ 17.8gr (my favorite), but with significantly more erratic velocities.

Accuracy fell off above and below 18gr for me, but I never went much higher to really see. The goal was a cheaper 125gr SST (my favorite) load.

For me, and surprisingly, 50 to 100yd accuracy was best with Wolf 223 primers followed by Tula then Rem 7 1/2.

Fed 205's had the most consistent velocity. I see that a lot with Federal, but they don't always give me best accuracy.

Oh, best is better than ok, but any best is fine, but not awesome and any ok needs work to really be ok. It's the erratic velocities that bother me most. Not that I can see that far to matter anyway.

125gr TNT
8.3" barrel @ 70°
2.100" OAL
18.0gr H-110

Wolf -- 1909.0 -- 101.1
Tula -- 1898.2 -- 67.2
Rem 6 1/2 -- 1884.5 -- 62.9
Rem 7 1/2 -- 1872.5 -- 61.6
CCI 400 -- 1869.6 -- 57.8
CCI 450 -- 1845.9 -- 53.4
CCI 41 -- 1918.8 -- 58.9
CCI BR4 -- 1942.3 -- 44.6
Fed 205 -- 1836.7 -- 29.1
Fed 205M -- 1847.8 -- 32.7
Win -- 1927.2 -- 45.9

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Re: Someone please help me understand these numbers!

Post by McAda441 » Tue Jan 21, 2020 9:11 pm

cdl wrote:
Tue Jan 21, 2020 5:37 pm
Might be of interest...

18gr - H-110 behind the Speer 125gr SST shot almost as accurate, and similar to my 125 SST's w/ 17.8gr (my favorite), but with significantly more erratic velocities.

Accuracy fell off above and below 18gr for me, but I never went much higher to really see. The goal was a cheaper 125gr SST (my favorite) load.

For me, and surprisingly, 50 to 100yd accuracy was best with Wolf 223 primers followed by Tula then Rem 7 1/2.

Fed 205's had the most consistent velocity. I see that a lot with Federal, but they don't always give me best accuracy.

Oh, best is better than ok, but any best is fine, but not awesome and any ok needs work to really be ok. It's the erratic velocities that bother me most. Not that I can see that far to matter anyway.

125gr TNT
8.3" barrel @ 70°
2.100" OAL
18.0gr H-110

Wolf -- 1909.0 -- 101.1
Tula -- 1898.2 -- 67.2
Rem 6 1/2 -- 1884.5 -- 62.9
Rem 7 1/2 -- 1872.5 -- 61.6
CCI 400 -- 1869.6 -- 57.8
CCI 450 -- 1845.9 -- 53.4
CCI 41 -- 1918.8 -- 58.9
CCI BR4 -- 1942.3 -- 44.6
Fed 205 -- 1836.7 -- 29.1
Fed 205M -- 1847.8 -- 32.7
Win -- 1927.2 -- 45.9
That's really neat to see the differences. In general I get better accuracy with these wsr primers when the case is slam full of powder. I'm grouping moa at best with 18gr but under half with 19gr. I've just had such good luck with the winchester primers that I'm reluctant to try anything else.

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Re: Someone please help me understand these numbers!

Post by McAda441 » Tue Jan 21, 2020 9:14 pm

Will think about switching primers though. Really hoping to find a load with the barnes 110gr, speer 125 tnt, and the speer 130gr varmint that I like and is under max pressure. I stopped annealing 300blk brass cause my damn primer pockets go before the brass does.

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