7.5 x 55 Swiss Very Long Term Project

I have been intrigued by the caliber for some time.

It seems quite doable with available brass now, use of the same 30 caliber bullets I have for the 308 and 06, some key powders in common.

I have the long action for it.

Nothing more than target shooting.

I don't see any reports of having been done.

Reamers might be an issue.

Oddly (to me but then I am not a big Lyman's reloading Handbook fan they have no loads even in the current one)

Good starting data in my favorite Hornady and Sierra

barrel would have to be 308 of course but that works fine for the bullets available anyway.

Thoughts?

You'll need to open up a .473 bolt face by about .030 or so. Other than that maybe some minor feed lip manipulation.

Actually, I have done this exact thing on a staggerfeed 110 action. I am also intrigued by the round. Hotolds442 is correct in opening up the bolt face a few thousanths, any gunsmith should be able to accomplish. I did not have to alter anything else, extractor, ejector on the bolt for it to work. I bought a PTG reamer and had a 308 Win barrel rechambered. You will need the long action or develop a load with a COAL to fit the short action magazine, or load one at a time. I have just began loading for the 7.5 and am still trying to find a good bullet/load. The GP-11 brass is reloadable if you can find berdan primers, just takes a little bit more effort to remove primers.

Here are a couple pictures,

http://i305.photobucket.com/albums/n...psy80mudzc.jpg

http://i305.photobucket.com/albums/n...psjgnhqr37.jpg

Nice. I have the 111 Project gun for the basis of it so the length is take care of.

Did you go with a 1-10 or 1-11 barrel? Spec says 10.63 original, seems either one would work well

The barrel just happened to be 1:10 and that's what I figured, either would work well. I have loaded up some 185gr Juggernauts that shoot pretty well, less than 1 MOA, but probably can do better since I'm not that great of a shot. I would like to find a lighter bullet that shoots well out of it also, but may have to have the throat reamed. The 185's I can load to length, but 175's and 150's hit the lands when loaded to length. I am new to reloading so still have a lot to learn.

I got back into reloading 6 years ago, more setup for Pistol but shifted over to rifle.

If the 150s and 175 are too long you can just seat them deeper. Unless running serious compressed powder it has no affect.

I use a Hornady comparator to get a close idea and then make them a bit longer until I hit the lands, then start setting back to see affect.

I have an old RCBS Junior I take to the range with me, load them all to max (assuming I have not hit on a good COAL yet) and then just start moving them back off.

Usually 10 or 15 are set to max and .005 off that.

I bring a bullet comparator with me (same tool, I made the Ogive adaptor out of a caliber I won't shoot) . I do have a digital micrometer (had it already so no cost there, you can get them for pretty low cost these days, $100 or so I think)

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Originally Posted by RC20

I have been intrigued by the caliber for some time.

I don't see any reports of having been done.

Reamers might be an issue.

Good starting data in my favorite Hornady and Sierra

barrel would have to be 308 of course but that works fine for the bullets available anyway.

Thoughts?

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I live in Switzerland, I shoot 7.5 x 55 Swiss and reload the same, I've pushed the calibre to 1025m, but luckily for me at altitude.
I've been pushing 190 grain Sierra Matchkings at 830 m/s. I've been reloading GP11 Berdan primed brass, I'm about to move over to boxer.

Living in Switzerland, 7.5 x 55 Swiss bolt faces are ten a penny... but its a pretty penny we have to pay. I'm running an Accuracy International which was originally chambered in 7.5 x55 from the factory, with a very propriatorey magazine that I cant get hold of anymore. I've modified the rifle over from a Prone/Dioptre rifle into a full blown "Sniper" setup. This involved ordering an AI Chassis (to replace the beautiful wooden stock that was too short) and having an gunsmith ream out the magazine well, as the chassis was a 308 fit.

What do you want to know?
for reference 7.5x55 barrels do differ from 308, the lands and grooves are different depths, but perhaps not enough to warrant much attention if you intend to use 308 bullets.

I used GP11 brass because I could acquired literally thousands of once-fired brass for free, and easily acquire primers..... it cost me a pretty penny in the hydraulic tool to eject spent primers tho.... but it was still worth it. The time saved vs a more mundane mechanical setup was worth the entry fee.

I used 190 grain Sierra Matchkings because they were the cheapest bullet by far, and they happened to fit my idea of a large range bullet.

I pushed that bullet pretty hard and my barrel life has suffered, I've completely burnt out the chamber end of the barrel. My accuracy is still .75-1 MOA so I'm not prepared to replace the barrel just yet, but its on the cards.

For the US market where I guess this originates from I don't see the point in going to 7.5 x 55 Swiss, when you guys have the 30.06 available. My specific action is tailored to the 7.5x55 Swiss, its neither long nor short, but something in between.$

While GP11 ammo is superb, I've managed to gain performance simply by pulling it apart and reloading it to tighter tolerances... the grains of powder in each case varied by several grains!

In short:
Reloading Berdan is a pain (I just bought 600 boxer 7.5x55 Swiss, but have thousands of berdan....)
Its going to cost you severely to tailor a US action to the round.
Performance is on par to 30.06.
Actual GP11 is a Match Cartridge I can obtain for 35 cents a round, so I'm sold, but its long range capability leaves much to be desired.

If you can obtain original GP11 in vast quantities for cheap it might be a worthwhile endeavor, but otherwise its eclipsed in cost effectiveness by a standard 308.
(its possible to load a 308 case to the same specs as standard GP11...I intend to do the same once my 308 arrives, as I've pulled many a GP11 Bullet)

Thank you for the write-up. Good information and enjoyed reading it. good to hear from Europe. I pick up a lot of the news that discusses that part of the world but miss the detailed takes on some of this sort of thing.

I do have the Bull 30-06 now. I like it!

Is the 7.5 a barrel burner by default or just when pushed?

Its more a kind of interesting and different project that I can manage without a lot of cost.

Current thinking is a Varmint Profile for a sleeker look. I have the chassis now thanks to a Cabalas sale and rebate.

One of the European barrel makers (Lothar Walhar who has a shop in the US ) has the 7.5 x 55 you can order (saves a step and cost by not having to send to someone else).

Pre a post here, you can get the reamer but a one time job and no experience with them if you can get a good pre-fit.

I shoot low levels normally but with a modern barrel you don't have the limitation's of pressure that the K31 has (or earlier)

Bolt head is a miner issue from the reports.

Brass can be had and best of all, Lapua with the Boxer primer which I think is the best mfg overall cost vs benefit.

According to the books you an shoot 308 in it, as the barrel may just be a 308 with the 7.5 chamber that may be even better.

I am into enjoying the shooting than a difficult project, this seems to be completely doable with minimum fuss and an unusual offering.

I could see doing this as a hobby when I retire. Kind of a niche product offering. Could be nuts, not hanging my hat on it.

Probably go with just a brass case fit up, save the cost of the gauges and start low, work up and see what the shoulder does on firing.

RC20, I'm like you, just something different without to much cost or effort. My barrel happens to be an LW, started as 308 and I had it reamed to 7.5x55.

Your one comment on shooting 308, I hope you mean 308 bullet diameter, not a 308 round.

Dioxin-I would like to here more about the hydraulic setup for removing the berdan primers. I have some GP-11 brass and 1000 berdan primers, so don't know if it would be worth it because berdan primers are somewhat hard to find here in the states.

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Your one comment on shooting 308, I hope you mean 308 bullet diameter, not a 308 round.

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I did mean 308 caliber bullets, but always good to check! (I surveyed when younger and cross check was mandatory, itty bitty tiny mistakes had huge consequence that you don't see in carpentry but on a survey huge (we had one that missed a monument by 6 feet because we assumed the line we started on was using right procedures, they were about 1/8 inch off, by the time we got to the section corner it was 6 feet, we stopped it at a fixed angle even fixed just made it that bad, if we had done what they did we would have missed it by a hundred feet as they were setup to keep drifting more and more left at increasing angle)

Nice to know others are interested and I am not just another Nut case (pun)

How does yours shoot? Best powder and bullet?

did the bolt heat work or did you have to open it up a bit?

Mine shoots okay, I have been able to get <1 MOA with juggernauts and IMR4350, but still working on finding bullet/powder/load combination. Haven't had much time to get to the range lately. I did have the bolt head opened up, it has worked fine. No changes to extractor or ejector needed.

I understand the survey (have done quite a bit in the past) and we were actually just talking about a similar situation the other day at work in regards to precision call out for angles on a pipeline.