What would you do?

[Josh06]

Good morning - want to get the opinion of the great members of this forum. I plan to try elk hunting in the fall so I put my 280ai on a diet with a lightweight scope and got a 20" cf barrel. My plan is to make up for short barrel by using Hammer 172 AH, trying to achieve 24-26" barrel velocity out of the shorter barrel. Went out last weekend and shot a short ladder with 6.5 staball in peterson brass. Only shot 1 for each load to get an idea of velocity and pressure, see below.
56.5 - 2814
57 - 2826
57.5 - 2868
58 - 2885

58 didn't show any signs of pressure but then 58.5 pierced the primer so I think 58 is max. 57, 57.5 and 58 created one ragged hole at 100yrds so I know I can find a good load in there around 2850ish. I think I should be happy with that and it would be above 2000fps out to 500 yards (which is max I feel confident shooting at animals right now). I've got 4000MR which is faster that I could try to chase some more velocity with but do I need to?

 

[cornshank]

Since you are asking for opinions ,load up some at 57 or 57.5
And shoot them at 200 ,300 ,400 and 500 yds, checking for signs of pressure along the way.
If all is still good , you should be good.
I do not have an opinion about the hammer 172 's
Never tried them.

 

[GLTaylor]

My suggestion is go lighter in bullet weight and faster in velocity. Look at the Hammer Hunter load data on this Forum. Lots of good data there!

 

[Shane Lindsey]

I would load at 57 and check groups and velocity.

If piercing primers 1.5gr above this, dirt, snow, moisture when hunting will also raise chamber pressure. Good to give yourself a little room to play with.

Lighter will give you better velocity as suggested. If 500 yards is your goal, lightweight ultra lasers will be your jam….

 

[TOM H]

I agree with cornshank. 2800fps + with 172gr is pretty good. I'm shooting R-26 in my 280AI and with 175gr ABLR mid 2900fps with 27" barrel and Peterson brass and that my best load. I live Co and range I shoot at is above 7K and I hunt around 9K/10K.

 

[vancewalker007]

I would load 57.7gr for seating depth testing unless you want to narrow down your powder nodes more. You could test something like 57.7, 57.9, 58.1 just to be sure you're in a solid node before you shoot a bunch of seating tests.

 

[LoneTraveler]

If the primer is piercing at 58 gr. load, May need to check the firing pin spring/ May need to replace the spring if no other signs of high pressure.

 

[vancewalker007]

If the primer is piercing at 58 gr. load, May need to check the firing pin spring/ May need to replace the spring if no other signs of high pressure.

I think the original reply says 58.5 caused the primer issue.

 

[Mike D Texas]

As others stated velocity is your friend with monos. I'd drop to the next lower weight class and/or fry a faster powder for more velocity. I personally like to be 3000fps or higher when I can and maintain accuracy.

 

[Josh06]

Thanks for the replies. I have some 140 AH on hand that I could test out as well. Looking at numbers though, if I push the 140's to say 3000 and compare to the 172 going 2850 at 500 yards there is only a 19 fps difference. Granted though I could probably push the 140's to 3100 at least (I pushed them to 3376 in a different 280ai). At 3100 they have a 100 fps advantage at 500 but the 172 is carrying 200ft-lbs more energy.
I have 10 172 AH loaded up at 57.5 Staball 6.5 to do some more testing. The only suitable faster powder I have is 4000MR so I'll do a small ladder to see if there is any more velocity there. I have 100V as well but its right next to Staball 6.5 on the burn rate chart and slower from all the published info that I have been able to find.