New Long Range Rig...not a Grendel though

[PredatorDown]

This may not be a Grendel, or even a 6.5, but I thought some on here might still enjoy this thing.

Several months ago, my brother-in-law decided he wanted an AR after shooting mine (both Grendel and 5.56). I told him I was looking into building a bolt gun, and he offered me a trade. I pieced together an AR in 5.56 for him, and I got his Remington 700 in 270WSM. He had owned it for close to 10 years, and had put a grand total of 40 rounds of factory ammo through it.



I knew it wouldn't stay factory for long, but was unsure what I would build it into. All I knew for sure is I wanted something that was capable at longer distances than I've been able to get with the Grendel. I'm pretty sure I've reached the practical limits of the Grendel and then some, but I can't complain with what I've been able to do with it. It will generally hold MOA to 1000yds, and I've grown fairly comfortable with shooting out to 1400. I have even taken it to a mile on occasion, which is what I consider to be beyond the practical limits of that amazing little cartridge.

One of the things that bothered me most was the factory trigger, so I knew that would have to get changed pretty quick. I've been sold on the feel of a 2-stage after putting the Geissele SSA-E in my Grendel, so the search began. Unfortunately there isn't a whole lot of options for a 2-stage in a bolt gun, but after a little digging I found the Tubbs T7T and placed an order.

That was pretty much it for a while other than having the barrel threaded. Then on Black Friday I got an email from JP Enterprises that their AMCS chassis was on sale for 25% off with 2 free mags. I hadn't been planning on it for a few more months, but between the 25% and free mags it was going to save me over $400 so I couldn't say no! Got it a few days ago and have been pretty impressed with the fit/feel/function of it so far. Had to do a small amount of inletting in front of the trigger to get it to fit, but it wasn't hard at all.





Took it out today for some load development and was both extremely pleased and kinda disappointed with what I tried. The mid-weight 130gr Bergers didn't shoot as well as I was hoping (about 1.5" at best), but the super-light 100gr Speer's shot lights out! 0.548 - .277 bullet diameter = .271 MOA!



Eventually it'll be rebarreled into a 7SAUM, but for the time being I couldn't just throw away a still brand new 270WSM barrel. I just figured for now I'd use it as my new coyote gun. Shooting those little 100gr Speers I have less than 6 minutes of drop at 500 yards, so it should be great for unknown distances out to at least that far.

All that's really left is the rebarrel to 7SAUM, a few odds and ends like accushot monopod, and eventually it'll be topped with a March 2.5-25x52.

And who knows, maybe by the time I get around to rebarreling it I'll have changed my mind into a 6.5SAUM. I've already got 200 Norma 7SAUM brass that could easily be necked down...

[LRRPF52]

That will make a nice ELR rifle for the time being if you can find a bullet that will stay spun. What twist does it have?

Is that bottom metal meant for the Short Action Magnums?

[PredatorDown]

I've actually never checked the twist myself, but from looking on their website every 270WSM has a 1:10" twist. According to Berger it's fast enough to stabilize their heavy 150gr VLD's, so the 130's shouldn't be a problem at all. I was also shooting their classic hunters, so they shouldn't have been as sensitive to seating depth. That's still probably the first thing I'll play with next time I head out.

I emailed JP a few months ago to see if the chassis would accommodate the WSM/SAUM line of cartridges, and they said they had built several rifles with that combination with good results. However, after trying mine the mags won't feed well at all. They're made to hold 10 7.62x51, but they claim they will also reliably fit/feed 7 of the WSM line. I'll most likely be getting an Alpha type 4 mag in the near future since they're designed specifically for the WSM's.

http://www.alphaindmfg.com/store/index.php?route=product/product&path=25&product_id=53

[LRRPF52]

I would also look at the Berger 140gr VLD for the .277" bore. Another one that Litz found to be much higher than advertised is the 135gr SMK with a .507 G1 BC.

The boat tail on it is really long, and the ogive is actually pretty streamlined. I've gotten really good accuracy from them out of my Pre-64 Mod 70 Winchester Featherweight, usually sub-MOA 3rd groups.

[PredatorDown]

Well I took it out again today to do a little plinking around with my brother in law and was pleasantly surprised once again. Shot a 3 shot 3" group at 490 yards with the 130gr Berger Classic Hunters, and I feel like I can still squeeze a little more accuracy out of it with some more load tinkering. I'll be heading to the North Springs range this upcoming weekend to stretch it out to at least 1000 yards to see how she does, and with any luck they'll let me set up and shoot at their 1500 and 1 mile plates as well. I'll be sure to report back when it's all said and done!

[GM2]

Very nice, look forward to hearing the 1,000 yard report.

[adamjp]

I emailed JP a few months ago to see if the chassis would accommodate the WSM/SAUM line of cartridges, and they said they had built several rifles with that combination with good results. However, after trying mine the mags won't feed well at all. They're made to hold 10 7.62x51, but they claim they will also reliably fit/feed 7 of the WSM line. I'll most likely be getting an Alpha type 4 mag in the near future since they're designed specifically for the WSM's.

I use the AI 5rd magazines with my 7mm SAUM. You simply need to bend the feed lips of the magazine box out so that they feed the fatter case. I get 4 down in the AI 5rd box.

[PredatorDown]

Went to a range on the desert today and stretched out the legs a little bit. Furthest steel was at 950 so I was able to get a pretty accurate representation of the rifle at distance. 5 shot group in just over 7.5" at 950 yards.

I think this is also a good example of why 5 shot groups are a better representation of your rifle's accuracy than 3 shots. My first impact was top left, then printed the lower three shots, final was top right. As much as I'd love to say I printed a 4" 3 shot group at 950, I'm actually more proud of a 7.5" 5 shot. Don't get me wrong, I love throwing out the occasional incredible 3 shot groups (I've shot a 3.5" 3 shot group at 960 with the Grendel) but that's more of an atypical result.

Either way, I'm pretty freaking happy!

[Kilco]

Old thread I know, but my love for this caliber mandates I commend you on not instantly re-barreling it and stretching the 270wsm out! My first bull moose, 950 pounds was shot with a 270wsm, over 10 years ago. Did have you seen berger new EOL hunting bullet for 277 cal? Don't remember the exact BC but I remember thinking it was so outrageously high that it's going to re-write the book on .277 long range. Something to consider if you haven't rebarreled already. (I love the 7MMSAUM as well but it's soooo hard on barrels)

[LRRPF52]

You'll need a 1/8 twist for that new Berger 170gr EOL .277 pill.

That's the other major problem with the .277 bore market, in that barrel makers don't typically make rifling tight like they do for 6.5mm and 7mm.

[Kilco]

Ah good point! I'm slightly biased against the SAUM cartridges though. Years ago, my brother and I each started our own custom builds. I used a r700 SA in 7mmSAUM and he used a r700 LA in 338 lapua magnum. First, I had to cut a little opening on my action in order to extract SAUM loads, and in 1000 rounds I needed to rebarrel. Think I was using a Hart barrel select grade.(nice barrels I still use them). Long story short, I sold that rifle years ago, he is still shooting his 338 with same barrel performing spectacularly. I know times, and equipment has changed alot since then, and those problems might be negligible nowadays.

[LRRPF52]

A 270 WSM is going to suffer barrel wear faster than a 7 SAUM since there is more overbore.

Brass for all of these cartridges is very expensive and of limited availability as well. I like them better than belted magnums, but cost to entry and to play continually is restrictive.

[Kilco]

Another good point... my old 270wsm was a pencil barreled factory win model 70, I still probably only have 4-500 rounds through it as it was, and has only been used for hunting thus far. Embarrassingly enough I just assumed it had less case capacity than the SAUM, and even most WSM cartridges. I probably should pay attention to wear on it though, thanks LPRPF52!

[LRRPF52]

If you use slower-burning powders and keep your chamber pressure low, you can have substantial velocity and excellent barrel life.

That is what George Gardner does with the 6.5 SAUM 4S. Keep chamber pressure below 58,000psi, preferably 55,000psi using large kernel extruded powder, pushing the 130gr VLD.

[bwaites]

I use H1000 in my 7mm WSM, and hunting barrel life is easily past 1500 rounds. Competitive barrel life is about 2/3, maybe 3/4 of that amount. I shoot reasonable loads, 2900-2950 FPS with 180 Bergers. I suspect I'm around 58,000 PSI, but that's a guess.

The guys shooting SAUM's in 6.5 must have magic barrels to get what they claim, though in their defense, they are shooting game and steel, which have a bigger target area than my 5" circle at 1000 yards.