Range Report: 22-250, 75gr Amax, 7828ssc

[Hondo64d]

Just starting to play with my 22-250. 700 action trued by Beanland and an 8" twist Bartlein 2b barrel pillar bedded in a Manners EH3. Looked through the manuals to see what burn rates were appropriate for this combo. I didn't see 7828ssc listed but saw several in that burn rate range so thought I would give it a try.

In short, I don't think 7828ssc is the powder for the 22-250 with 75r Amaxes. I loaded and shot 8 different charges in .4gr increments starting with 35.2gr and ending with 38gr. Bullets were seated to lightly kiss the lands. Runout was extremely low, with most being < .001" (gotta love Lapua brass!). I got one group that was about .5 MOA and two groups that were in the .6 MOA range (5 shots at 300 yards) but the rest weren't very good and the highest two charges quite awful, approaching 2 MOA. It was interesting that with the highest three charges, the velocity nearly quit climbing, with averages increasing less than 7 fps with each .4gr. increase in powder. Max average velocity with 38gr. was 3139. Extreme spreads were not very good and some quite bad. The higher charges had extreme spreads as high as 67 fps.

I've now loaded up some H4350 to see how it likes that.

John

 

[JAnderson94]

Do you think results would be different with an Ackley case? I was actually tempted last week to try this combo in my ackley but decided against it for right now.

 

[357Mag]

Just starting to play with my 22-250. 700 action trued by Beanland and an 8" twist Bartlein 2b barrel pillar bedded in a Manners EH3. Looked through the manuals to see what burn rates were appropriate for this combo. I didn't see 7828ssc listed but saw several in that burn rate range so thought I would give it a try.

In short, I don't think 7828ssc is the powder for the 22-250 with 75r Amaxes. I loaded and shot 8 different charges in .4gr increments starting with 35.2gr and ending with 38gr. Bullets were seated to lightly kiss the lands. Runout was extremely low, with most being < .001" (gotta love Lapua brass!). I got one group that was about .5 MOA and two groups that were in the .6 MOA range (5 shots at 300 yards) but the rest weren't very good and the highest two charges quite awful, approaching 2 MOA. It was interesting that with the highest three charges, the velocity nearly quit climbing, with averages increasing less than 7 fps with each .4gr. increase in powder. Max average velocity with 38gr. was 3139. Extreme spreads were not very good and some quite bad. The higher charges had extreme spreads as high as 67 fps.

I've now loaded up some H4350 to see how it likes that.

John

Hondo -

Howdy !

I shot a wildcat .22-35 Rem in a 28" 1-8 K & P some years, after first trying the wildcat from a 24" 1-14 Hart. .22-35 Rem has case capacity between that of .22-250 and .22-250 AI.

I shot 75"A"-Max exclusively in the 28" 1-8, using it for shooting both soybeanus digestus; and for target work. I went for best accuracy w/ practical/usefull velocity.

Since WW760 and VV160 worked the best shooting 55s from the 1-14, I knew I needed to go w/ a slower burn rate powder when shooting the 75s.

I'm a believer in " high load density ". In my gun/my loads, powders like VV160,VV560 , RL-19; and H4831 were all too fast on " burn rate ".

AA3100 ended up coming out above the rest. I did not have any specific vel goal in mind.
My accuracy load was: 40.5gr AA3100 and FED LR Match for 3,420fps.
Just switching primer to use of FED LR Magnum Match boosted vel to 3,500fps, w/ a slight opening of the groups. I wenbt w/ the regular Match primer.

You may have a higher vel goal in mind, and going w/ something like H3450 is understandable.
I' ll mention the newer IMR4451 as another potential cadidate in that burn rate range, and it is formulated to be pretty temp insensitive.

As regards IMR7828 use:
I use it in my " DEEP 6 " wildcat, under 6mm bullets of 95 - 107gr.
DEEP 6' case capacity is 51.2gr H20. Even in that large of case capacity in 6mm calibre and those bullet weights..... IMR7828 gave slower vel than many shooters might accept. Burn rate too slow.
Accuracy though, was/is phenomina !

If you want a powder closer to IMR7828 than to H4350, the new IMR4955 might deserve a look ?


With regards,
357Mag

 

[Hondo64d]

Do you think results would be different with an Ackley case? I was actually tempted last week to try this combo in my ackley but decided against it for right now.

I really don't know. I have run the 7828ssc in my son's .270 with some pretty good results and also in the .260 Rem with pretty good results. The 22-250 sure doesn't like it though.

John

 

[cath8r]

I have a .22-250 built by Dennis Sorensen. It has a trued rem 700 action in a stainless mcgowen #3 contour (I think) at 22.5". He throated the chamber for the 75 gr amax to just get into the rifling. 2.565" oal and 36.5 gr H4350 get me about 3150 fps average. I find accuracy excellent (for me). My best 3 shot group was about 2" at 300 laying prone off of bipods. It was built as a windy day coyote rifle in mind. Wears a leupold vx3 2.5-10 with cds dial.

 

[John from MN]

Do you think results would be different with an Ackley case? I was actually tempted last week to try this combo in my ackley but decided against it for right now.

I've had excellent results with slow burning powders such as H1000 and Ramshot Magnum in the AI version. The standard 22-250 case doesn't seem to care for them one bit.

Both powders gave excellent accuracy with the AI case out of a 26 inch barrel at 3275 to 3300fps.

 

[Hondo64d]

I just finished shooting the 4350 loads. I shot these at 100 because the wind was a little squirrelly. I started at 34.8 and went up to 36.4 in .4gr increments. Groups got progressively tighter as the charges increased and extreme spreads decreased. Best group was at 36.4gr with four of five being in about .4" and a flyer that opened it up to about .8". That one averaged 3210 fps. Bolt lift was getting a little harder at 36.4gr but primers looked good and no ejector hole marks. I was encouraged by all the different charges hitting the same POI. If you stacked all five targets on top of one another, the entire 25 shots would be less than two inches. Were it not for the lowest charge, they all would have gone into about 1.25". Extreme spreads were much better than with 7828ssc but still not nearly as good as I would like, with the top two charges showing 38 and 39 fps extreme spreads. I think I'll bump it up to 36.6 and see what it does.

If I don't see what I'm looking for, I'll move on to R15.

John

 

[cath8r]

If you don't mind me asking, what are you using yours for? Things sound like they are coming along for you.

 

[Hondo64d]

If you don't mind me asking, what are you using yours for? Things sound like they are coming along for you.

Playing on steel out to 800 yards and hunting, everything from jack rabbits to whitetails.

John

 

[dtucker]

Try some Varget and 4064 will surprise you.