6.5 Sherman Shortmag Load Data

[RH300UM]

Good point Rich
I am also using HBN in the bullets.
Should have stated that.

 

[elkaholic]

Good point Rich
I am also using HBN in the bullets.
Should have stated that.

That is good info but even more puzzling? I don't doubt your data one bit, but that should lower your pressure even more? Goes to show the individuality between rifles....Rich

 

[RH300UM]

All speeds from a magneto chrono.

 

[elkaholic]

All speeds from a magneto chrono.

Mine too!

 

[elkaholic]

Here is the latest data on the SS. I have been shooting the 143 ELDX with good accuracy and velocity with RL26, mostly .3's at 3200 and change. I decided to try some 7977 today, and threw in one volley with H1000 which I had not tried yet with the ELDX. The 7977 only shot about 1/2" with 3 different charges, but the one group with H1000 was pretty impressive. This was not a max load, it would make over 3200 before maxing out.

 

[elkaholic]

I went back out to proof the 61.5 gr. load and did even better so I guess I may have a keeper! I also shot this 2 shot load with 62.4 grs. (all I had) This H1000 is looking mighty good.......Rich

 

[tbrice23]

Holy God Rich,
What brand barrel are you using?

Sounds like you may be switching to h1000 instead of rl26.

 

[elkaholic]

Holy God Rich,
What brand barrel are you using?

Sounds like you may be switching to h1000 instead of rl26.

It's a 26" 3b Bartlein 5r, 8 twist. I am not giving up on RL26 because it shows so much promise. However; with the temp stability, and that kind of accuracy, I may be using H1000 in this combo......Rich

 

[KMG]

I went back out to proof the 61.5 gr. load and did even better so I guess I may have a keeper! I also shot this 2 shot load with 62.4 grs. (all I had) This H1000 is looking mighty good.......Rich
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Hey Rich with that 2.988 coal, how much are you jumping those? I figure our chambers should be similar in dimension being cut with your reamer & all . Ijust picked up a few 100 of the 143's for testing. Thanks, Kevin

 

[elkaholic]

Hey Rich with that 2.988 coal, how much are you jumping those? I figure our chambers should be similar in dimension being cut with your reamer & all . Ijust picked up a few 100 of the 143's for testing. Thanks, Kevin

Hi Kevin.....they are a very long bullet. I am jumping them approx. .020", but they are not as finicky as a lot of bullets.....Rich

 

[KMG]

Thanks Rich. Wow, they gotta be long, I like it. I haven't even looked at em yet. Just to busy. I finally got my hands on some rl26 as well. Really interested in what kind of velocity I'm going to get over rl33. I'll post my results when I get out.

 

[KMG]

Well looks like RL26 definitely is a boost in velocity over RL33. Got out the other night to run a quick ladder to find max. Set up my cheep chrony , fired 3 rounds to confirm velocity of my standby 65 grains RL33 & 140 Hybrids. Velocity 3168-3184. Ran RL26 with the 140 Hybrids for apples to apples comparison. 60 grains 3234,3242; 61grains 3284,3304; 62 grains 3338, 3358!! The 62gr load had ejector marks & stiff bolt lift but not too bad. I think if I would have gone to 63 it would have cracked 3400'. There were 20-25 mph winds so I wasn't concerned about accuracy, but all 6 shot in a nice cluster. Looked like 60-61 was a good pressure range for next outing. Thinking I can get 100 fps increase in just the powder switch.

 

[elkaholic]

Hi Kevin....Looks like you are having fun with the SS! Pretty impressive velocities with the RL26. I would add though that 65 grs. of RL33 is a pretty mild load with a 140. I can shoot 66 behind a 160 Matrix for 3130' in a 26" barrel. Keep the data coming.....Rich

p.s. Not knocking your Crony, but you may have more velocity than it is reading. My magneto speed gives me 3305' with 60 grs. RL26 behind a 143 with only a 26" barrel. I would think you would gain more than 35' with a 30"?

 

[KMG]

Hi Kevin....Looks like you are having fun with the SS! Pretty impressive velocities with the RL26. I would add though that 65 grs. of RL33 is a pretty mild load with a 140. I can shoot 66 behind a 160 Matrix for 3130' in a 26" barrel. Keep the data coming.....Rich

p.s. Not knocking your Crony, but you may have more velocity than it is reading. My magneto speed gives me 3305' with 60 grs. RL26 behind a 143 with only a 26" barrel. I would think you would gain more than 35' with a 30"?

Hello Rich, Don't worry about knocking my chrony I do it all the time. Lol! Using my drop data is where I fine tune my velocity anyways. Yes I ran 67grs. of RL33 with the 160's @ 3186' so yes I may be leaving a little velocity on the table but I think you said it "Pretty impressive for an idy bitty case". I believe I have a slow barrel anyways. It has sped up some after a couple hundred rounds not much, but some. Going to give 26 a try with the 160's next outing 56-61grs. Thinking with the gains with 26 & the 140's it should top 3200 maybe 3300.

Just wondering if others with 26+" tubes have been getting any substantial velocity gains with the added barrel length?