7mm rem mag advice

[ILVSMOG]

I've started playing with the 145gr Barnes LRX in my 7mm Rem Mag and I could use some advice. It likes about .050 off the lands (3.300" oal), but the best accuracy I've been able to wring out of it is at only 62gr of H4831sc. I've tested up to 65gr (book max is just under 64gr). I saw no pressure signs at 65gr, but the accuracy just wasn't there. Do I need to lean on this thing harder? 66?67? Anybody more experienced with 7rm please chime in!

Thanks!!

[devster55]

What kind of rifle is it? I am experimenting with those rounds as well and am using IMR 7828SSC right now. I don't have a range report yet. As soon as I do I will let you know. What's your group size?

[Divernhunter]

Try changing powders and use mag primers in all loads.

[ILVSMOG]

Remington 700 action. I'm already using magnum primers. I've got some RL25, but I like the temp stability of the H powders.

[devster55]

I have always had good luck with IMR powders. My rifle is a weatherby and my fathers is a winchester. We will be trying my loads in both rifles. My rifle currently shoots a 3 shot group with all rounds touching at 200 yds on the bench.

[allenj]

You've said something that has me confused:

(book max is just under 64gr).

What book are you referring to?

The loads I've worked up are using WMLR primer and 58.0 grains of IMR4831. COAL is 3.245.

[ILVSMOG]

I'm referencing Barnes load data for that projectile.

[allenj]

I would be very interested in that data if you don't mind, I love the LRX bullets and am currently loading them in 5 different rifles in 3 different calibers. Do you mind sharing it?

[ILVSMOG]

Per Barnes:
7mm Rem Mag 145gr LRX

Powder start charge (v) Max charge (v) Load density (%)

H4831SC (Hodgdon) 54.2 2629 63.8 2969 91
IMR 4831 (IMR) 52.6 2593 61.9 2996 88
PowerPro 4000MR (Alliant) 54.5 2642 64.1 3063 92
RL 22 (Alliant) 52.2 2641 61.4 2989 91
IMR 7828SSC (IMR) 55.9 2588 65.7 3017 87
H1000 (Hodgdon) 58.5 2637 68.8 3022 99
Magnum (Ramshot) 63.8 2687 75.0 3106 104

[allenj]

Thank you sir.

[scotty99]

I've had good luck with Hybrid 100v in 7mag with the lighter bullets. And Barnes bullets always seem to prefer being loaded to the very top end of the range.


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[spamsucker]

Honestly, accuracy in 7mag for me has always depended on 1 thing, IMR 4350. I've never had as good of a result with any other powder and I've tried a lot of them. Normally I get best results at ~1 grain under book max.

[Whiterabbit]

You have an accuracy node at 62 grains. I'm gonna assume there's some powder space left in the case because you tested more and found less accuracy. That's OK. 62 is great if you have a node there.

I know you already said you load .05 off the lands. Have you considered trying seating the bullet deeper? Up to and including all the way down to put the ogive at the case mouth, assuming you aren't compressing the powder too much. Do you have that much bandwidth for seating depth?

I have found this can improve precision with Barnes bullets. Ideally, you are loading to 100% case fill. In this case, bringing the bullet down into the powder where your accuracy node is, rather than bringing the powder up to where you percieve the bullet wants to jump from.

I ask, because I have found barnes bullets (IME) are not sensitive to lands distance like Bergers. In fact, in my guns I have found they like a little jump. And I suspect you will find that that will bump your velocity up a bit as well (which seems to be what you want to do, given the way you are asking your question.)

[ILVSMOG]

I hadn't considered shortening the load. I think 62gr is under 90%, and there definitely seems to be room in the case. I didn't go any shorter than 3.200" in testing, because there wasn't a trend towards improvement there. I guess I could revisit a shorter OAL.