7mm rem mag velocity

[OU812]

I am not having any luck with velocity these days. Shot my friends 7mm rem mag with the very accurate load of a 160 AccuBond, fed 215, 62 gr RL22 but the velocity is 2780, book shows velocity should be high 2900-low 3000. Shot some factory fed 160 accubonds and they chronod 2980, listed at 2950. What on earth is going on with this load?

Any one have a good accurate higher velocity load for the 7mm rem mag with a 160 AccuBond?

Bill

 

[SJB358]

Bill, for some darned reason, I see alot of data showing 62-63gr of RL22 in a 7RM with a 160 stating around 3K. I have NEVER seen any 7mm do 3K with less than 65gr's of RL22 and most do it around 66 in my loading. Your speed is identical to what I was seeing in mine. 65-67gr's seems to be the magic number for the 7RM and consequently the 7WSM as well. Not sure how they get their speed, but it would have to be a really small case with a tight chamber. I would add some more coal to it. I would bet you will get 3K or better really easily out of the 7RM. Heck, your load is even a little less than I have run 175's for the 7RM. 2900 with the 175's is fairly easy for the 7RM with around 63-65gr's. Sierra lists 65gr for their 160 and RL22.. Probably the closest I have seen to realistic load data for that cartridge. Scotty

 

[OU812]

Bill, for some darned reason, I see alot of data showing 62-63gr of RL22 in a 7RM with a 160 stating around 3K. I have NEVER seen any 7mm do 3K with less than 65gr's of RL22 and most do it around 66 in my loading. Your speed is identical to what I was seeing in mine. 65-67gr's seems to be the magic number for the 7RM and consequently the 7WSM as well. Not sure how they get their speed, but it would have to be a really small case with a tight chamber. I would add some more coal to it. I would bet you will get 3K or better really easily out of the 7RM. Heck, your load is even a little less than I have run 175's for the 7RM. 2900 with the 175's is fairly easy for the 7RM with around 63-65gr's. Sierra lists 65gr for their 160 and RL22.. Probably the closest I have seen to realistic load data for that cartridge. Scotty

Nosler list 63gr of RL22 as max for the 7mm rem mag. I think I'm goin to try 7828 with the 160 accubonds and if that don't do it RL25 will be next.

 

[Bruce Mc]

I have also found around 66+ grs of Reloder 22 needed for 3000+ velocity. Very few ballitstics labs use hunting rifles for pressure testing so making a comparison is not always exact. No reason not to try those other powders, but I expect you'll have a very similar result. I use H-1000 for my 160 AccuBond load but I had to go a bit over book max to get the advertised 3000+ velocity. But the load doesn't have any pressure indicators and my brass is not strained.

 

[SJB358]

7828 is supposed to be a killer in the 7RM too. I have found they run about the same for a given charge. Either one of them are about the tops for the 7RM I have found. Although, I have put together a ton more loads with RL22 as I usually have more of it around the bench. Maybe see if you can have someone run you a QL for the 7 with 160's. That might get you some more accurate data? Scotty

 

[OU812]

Scotty and Bruce, thanks for info and reassurance. 7828 is going to be my next choice in line.
H-1000, I have used that in the past with good results, worth a peek see for sure.

Bill

 

[JD338]

Bill,
I agree with the others, you are going to have to bump up the charge weight of RL 22 to 65.0-66.0 grs to hit 3000 fps with the 160 gr AB.

JD338

 

[DrMike]

While it is not possible to make a strict correlation between velocity and pressure, there is nevertheless a relationship. I'll give you some advice I received from a great ballistician. Work up in half grain increments, watching for pressure signs to increase velocity. You may have a somewhat faster lot of powder, the bore of your rifle may be wearing somewhat, or you may be witnessing some erosion at the throat. Any of these conditions would allow for a loss of pressure and hence, a loss of velocity. I measure 3164 fps with a 160 grain FS and 66 grains of RL22, and 2976 fps with a 160 grain AB and 63.5 grains of RL22.

 

[OU812]

While it is not possible to make a strict correlation between velocity and pressure, there is nevertheless a relationship. I'll give you some advice I received from a great ballistician. Work up in half grain increments, watching for pressure signs to increase velocity. You may have a somewhat faster lot of powder, the bore of your rifle may be wearing somewhat, or you may be witnessing some erosion at the throat. Any of these conditions would allow for a loss of pressure and hence, a loss of velocity. I measure 3164 fps with a 160 grain FS and 66 grains of RL22, and 2976 fps with a 160 grain AB and 63.5 grains of RL22.

I don't know the history of the 7mm as it belongs to my friend. I do know it spit out the factory 160 accubonds 50fps faster than listed on the box. I really thought we would see 2950ish with 62 grains of RL22. There does not seem to be any signs of over pressure at 62 grains so maybe .5 grain increases are inorder.

 

[DrMike]

It sounds as if your lot of powder is perhaps faster than others might have proved.

 

[baltz526]

RL22 at 65gr gets me a 3013fps average in a 26" using the 160gr AccuBond. But i was not happy with accuracy in my rifle. It shot pretty good with them in 7mm08 velocity area in the rifle. The lyman book is where i go for most of my data. A couple powders i have had great results from in the past have been IMR4831 and H4831. with 160gr in the 7mm rem mag 2950fps to 3050 is about what i expect.

 

[FOTIS]

66 rl22 is my standard in the 7 remmy

 

[Jimbeaux82]

I dont know about what you guys do, but I look at the manuals and get the maxium velocity listed for the bullet and powder - which I almost never get out of my hunting rifles.

Then , using a chrono, I increase the charge weight, carefully monitoring for pressure signs, until I get the velocity listed as maximum and then I call it quits. I dont try to go past that point at all. I usually see exactly what you have indicated, taking several grains more powder to get the max velocity listed.

So far, I have not gotten in trouble with this method and the chrono is absolutely necessary to do this.

 

[C.Smith]

66 rl22 is my standard in the 7 remmy

I had the same velocity woes as you are having with my 7 mag and tried the above load, working up to it of course. I currently push the 160 AccuBond at 2988 fps and a five shot group of:

I would give it a try.

Corey

 

[DrMike]

Not bad, Corey. Not bad at all. In fact, that could just qualify as enviable. Good post.

 

[SJB358]

Great target Corey. That Savage is a shooter for sure. I have found the 160gr AB in my 7WSM with RL22 is very good as well. Scotty

 

[filmjunkie4ever]

That is good shooting bud!

For what its worth, the load I tailored for a friend with a 7mm Rem Mag in a Remmy 700 with 24" tube was a 160 grain AccuBond on top of 69 grains of H1000 ignited by FED 215 Mags was getting about 2950-2975 fps. It was darned accurate too!

 

[C.Smith]

Thanks, it is my do everything load, thanks to POP.

Corey

 

[Jimbeaux82]

66 rl22 is my standard in the 7 remmy

I had the same velocity woes as you are having with my 7 mag and tried the above load, working up to it of course. I currently push the 160 AccuBond at 2988 fps and a five shot group of:

I would give it a try.

Corey

Impressive, Obe Wan, impressive

 

[OU812]

66 rl22 is my standard in the 7 remmy

I had the same velocity woes as you are having with my 7 mag and tried the above load, working up to it of course. I currently push the 160 AccuBond at 2988 fps and a five shot group of:

I would give it a try.

Corey

Wow! That's a shooter. I will encourage him to try as such.

Bill