Thread: 7mm RM 162 Amax

Evening.

Been trying to find a load for my 22" barrel Rem 700 7mm Rem Mag. Wondering if you intelligent buggers might be able to offer some advice.

Using 2225 and Federal Magnum Match primers and starting 1gr below min as this is what the previous owner was using (worked well for him, i just can't seem to replicate it). Working up in 0.5gr 5 shot groups to 72gr where i ran out of brass to cont. No pressure signs from my basic knowledge. and max load stated by ADI 73.5gr compressed.

Sorry i don't work in inches but again previous owner supplied me with a OAL and when measured some loads supplied came to 68mm with hornady comparator. Just checked with OAL gauge and to get it touching lands, the boat tail is only just in the neck of the case (as per pic). I could seat the projectile 5 - 5.5mm further out and it would still fit the mag box but would be able 2.5mm off the lands.

Where would you go from here?

Pictures of target were unfortunately short in a stiff breeze (also not the best shot). First lot wind L to R and second R to L (different days)
Many thanks

You need to remove some of the variables and state some of your goals.

Is this to hit gongs at distance, target or hunting - the need will shape the direction you may want to take with the load you're after.

Also you state a stiff breeze - most likely not consistent select a day that is almost dead still and if you can the morning or late afternoon (if for hunting use this would aproximate animals being around).

What contour barrel being fired from standard 700 contour, varmint like a heavy 5R etc - will determine any heat walk to be expected with hot loads or lots of rounds with little time between for barrel to cool.

Do you have a supressor? if yes removes a chance you developed a pull or flinch over the time shooting for the day. if not did you notice starting to flinch or better have someone watch you for this.

The key to this stage of selecting or narrowing a load is about consistency and maximising the situation that you did exactly the same for each shot or calling it when you deviated.

You've made a good start - don't be discouraged... there's lot to eliminate to uncover the real learning's

PS. don't forget your sweet spot for hunting and target might be a lot more south of the Max loadings in the guide than you think. mines 63.5 of IMR 7828 cloverleaf... Just saying.

Thanks for the reply.

Hunting mainly but always nice to have a shot at the gongs as well. Or most other pests that happen to land at the range.

I would normally try for a still day but just hasn't been happening lately.

Standard contour Rem XCRII. Fired the 5 shots then removed the suppressor waited until rifle and supp was cold before next 5.

Hopefully not flinching. Have had people watch me before. Had it resting on sandbag and a towel folded over a few times on the shoulder as a bit of padding. Wearing earmuffs as well.

Cheers

If thats the my targets varmit the, grid is in half inches so the second targets groups are round 3/4in assuming shot at 100. Not too bad for hunting if shot closer parallax could be a factor.

A towel folded over on the shoulder? I would say that's a pretty big part of you problem. Do yo plan to hunt with a towel for your shoulder?

Yea I agree with Henry above, that's not to bad if shot at a 100m, and its half inch target grid, and it looks like it to me, I would go with the loads #8 and 9 and do a bit more testing,
general rule, is you want at least the dia of the projectile to be in the case, you don't have much for the brass neck to grip on, and may not be getting all your ammo centering in brass, I would likely, try seating a bit deeper, don't worry about chasing the lands, I have a very accurate 6mm Remington M700, and a 7x57 M70 shooting 162 a-max, with lots off jump,
shoot five shot groups, and try a few different seating depths at around, 71-71.5, any one can fluke, a good three shot, 4-5 tell the real story.
22" 7mm rem be a barky bastard, without a suppressor, likely start to affect shooting.
You should also have a think, about what you are trying to achieve, chasing little groups, with bench rest accuracy, or a accurate hunting rifle, ( looks pretty good to me)
If those boxes are 1/2, then you have two groups, at around 3/4 inch (19 mm), have a think about what that means, not enough do,
A 3/4" (19mm) group means that every shot, has landed with in 10mm of your point of aim, at a given distance, not bad aye.

Looking at his thumb they aren't half inch squares, they will be inch squares. The throat on your rifle seems really long, my 7mm mag with amaxs had heaps more of the projectile in the case.
I wouldn't bother with 5 shot groups, when hunting it is the first shot that counts. A lot of 7mm mags shoot 73ish grains 2225 well. If you seat your projectiles right out then 73gr won't be max or compressed.
Use what the brass/primer is telling you about pressure, not a book. Look at the edges of the primers after firing. An unfired primer in the case will have a nice round radius on the edge. As the pressure increases the amount of the radius will decrease. If the primer has no radius you are over pressure.
Don't worry too much about a crater around the firing pin strike, this is more a case of a large firing pin hole in the bolt rather than excess pressure.

With my 7mm mag and 162 amaxs i fired one shot at each weight of powder over a chronograph until I hit the velocity I was after, checking with pressure as I went. Then I loaded three at that weight, went 0.7MOA load development finished. 12 rounds fired. I shot animals out past 600 yds with that load, all one shot kills.

Thanks for all the replies. The squares are 25mm/ 1" so not that small. And at 100 yards.

The towel just helps when firing off 20-25 rounds in one sitting. But no don't generally hunting with a towel on my shoulder. But do generally wear a base, mid and top layer so comes close considering it is a tad warm and just in a t shirt.

The photo of the projectile next to the case is touching the lands. At the moment they are seat 10mm deeper than that. Was saying I could probably seat it out 5-5.5mm more and still have at least 7mm in the neck.

Most of the groups would have been 5 shots. But the others got sent slightly off target towards something else.

So far the loads that were supplied have been quite consistent (when I do my part) at hitting an A4 gong at 500. But think I fluked a very small group with them and can't replicate it loading how he did. So just wanted to see if I could make it better.

Cheers again for the replies. Will try a couple different loads around 71.5 plus just a couple higher to check.

I was checking the brass as I went. No flat primers and no marks from the ejector pin. A little crater around the firing pin but it is a Remington and it isn't in the centre. So guessing the hole is probably a little sloppy.

Can only guess where your 10mm deeper seating would be but I would seat for a starting point, in your case, so that the point on the projectile where it changes from the boatail section to the parallel shank lines up with the shoulder neck junction on the case. Assuming your powder charge is not being compressed by this seating depth - it shouldn't be. With your long throat I wouldn't even bother chasing the lands. I have a 22/250 that I cannot get within cooey of the lands and it shoots exceptionally well still. A cartridge loaded as shown in your photo with the projectile so far out, if dropped on the floor, would develop a severe case of runout/wobbles. When dropped they always land on the projectile end of course. Also consider when developing a seating depth the max mag length limitation.

I am not seating the projectiles as shown in the photo. That was just to show where the lands where. If I seated it 3mm deeper it would fit the mag box with room to spare. Which would give about 7mm in the neck. The loaded rounds I have already would have close to 12mm in the neck. Just was wondering if it would be worth bring it out more. Like someone above suggested I will try around the 71.5 mark and different depths.
So far at 72.0 looks like still plenty of room so I wouldn't imagine 73.5 compressing.

Thank you for all the help so far.

I'm not so sure there is too much wrong with some of your groups.
When you can put 3 out of five inside what looks like an inch square off a magnum rifle, so long as your rifle is bedded and all screws are tight things aren't that bad.
Looking at what you have achieved the previous owners claim does not seem to far fetched.

I'd look at you, your reloading, or your shooting position.

for 2 of my mates tikkas that i load for coal is 83.5mm with 73grn of 2225 with 162amax. (fits in mag) with good results out to 1km

Just shoot three shot groups for a start. Don't waste ammo, use it for making steak.

Do you reckon the last owners claims of acuracy is true? i.e are you usually a good shot and are you used to a rifle with a hard recoil?

Ill try a few more loads then play with the seating depth. I appreciate the help and hoping in the next week post a result.
Cheers