7X47 Loads

[Aussie_bob]

OK have received a 7mm 10 twist barrel and the mate is chambering in in 7x47 Lapua we neck-sized the cases and he is making the reamer hopes to have it ready to shoot next week. Even though he is retired he gets quite a bit of tricky work making specialized tooling.
What we need is a starting point for loads will be using 145gr HPBT Speers looking at using H4350 or H4831 up around the 40gr mark, anyone tried 140gr pills in the 6.5X47 with either of these powders. Would like to get up around 2800Fps or better.
Any help appreciated.

 

[Aussie_bob]

Well looks like we are flying in the dark on this one i see at least 50 people have had a look but seems no one can give us any idea of a starting load. With this case i should think we could fill it to the base of the shoulder or maybe a little more with slower powder and still be fine. Thinking around the 40 to 44 grains.

 

[NeilNE]

Well, I'll give you a suggestion. The closest case off hand is a 7x57 or 7-08. About .2 to .4 longer. I would start about 2 grains below loading book suggested load and work up one grain until I see the start of flat primers. Then 1/2 grain after that. I would only shoot one or two shoots for each powder. I shoot a lot of wildcat cartridges that I make up and this is how I do it.

Good luck

 

[Aussie_bob]

Well the 7X57 that we are rebarreling and coming back to 7x47 we will start with a case full to the neck as the 7X57 would take 55 grains of the powder we were useing in it so with discussions with other we will start with the case full to the neck with this powder which will be around 10grains less will see when we get closer may have to go to a slightly faster powder.
Also he is now going to use 130gr Sierra Match Kings when they arrive.

 

[NeilNE]

A case full to bottom of neck sound like it might be a 100% or compressed load. To much for me to start off with.

The 7x47 sounds very interesting. Keep me informed if you can. Good luck!!!!!!!!!!!!!!!

 

[Aussie_bob]

Well just an update for those who may be interested.
We fire formed a few cases today using 40.5gr H4350 and 140gr Projectiles absolutely no pressure signs and after fire forming the case will hold 44grs to the base of the neck these rnds where only fired in a test sound dampened pipe so no chance to check velocity.
I will be leaving for Sydney Wednesday and be back the following week so the day after i get back we will take it all to the range and start some serious testing with a selection of powders. Also by then we should have some Match grade projectiles to try.

 

[NeilNE]

Keep us informed! Sounds very interesting. Post Vel. please.

 

[Aussie_bob]

Further update.
After fireing a few rnds in the pipe and cleaning after each we finally got a chance to head to the range with the chrono.
Our fire-forming load was good and seeing as how we had been fireing and cleaning in the pipe and no fouling decided to try ten rnds. Will attach the pic of first ten rnds fired at the range.velocity isn`t what we would like but we only had sierra 140gr game kings to fire-form with still waiting of the 130gr match kings.
The shot to the left is the first shot wound scope up and right and decided to just shoot the other 9 conditions where not good 20mph winds but we were mainly interested in fire-forming. Powder was ADI AR2209 or equiv H4350 40gr and 140gr projectile seated .010" into the lands.
After fire-forming 40.5grs produces about the same 2500fps with SD of 6.
While fire-forming we did .6 groups of 20 shots the group shown is .6"

 

[NeilNE]

The 9 shoot group look good for first time out. Keep us informed. What angle shoulder do you have,30 degree ????

 

[Aussie_bob]

Yes 30 deg shoulder when we have access to better projectiles we will try other powders as well see if we can get velocity up without pressure.

 

[Aussie_bob]

Well finally have 100 130gr Match Kings and a 500m shoot on this weekend so really cutting things fine.
Went to the range today, finished fire-forming the rest of the cases with 40.5gr Ar2209/H4350 & 140gr Game Kings 2550Fps Loaded 130gr Match King 39grs Ar2208/Varget and low and behold 2880 to 2890 Fps and after playing a little settled on 39.2grs AR2208/Varget with the projectile .010 into the lands velocity at 2890 measured with a Ohler #33 end screen 20 feet in front of muzzle last two 5 shot groups had an SD of 5 & 7 there are no vi sable signs of pressure as yet and we feel you may even get up to 3000 fps tho one load of 39.6 reached 2947 and bolt was hard to lift Possibly H4895 would work well will have to wait till we have more time but at present very happy with the results. We were achieving over 2900Fps jumping the projectiles but SD was 14 or more, once we jammed them SD dropped and also velocity one group had an SD of 2 would love it to stay there but don`t think it realistic long as its in single figures we are happy.

 

[NeilNE]

Sounds like you have a winner!! Just what I wanted to hear, another cartridge to look at. I like to shoot at 2850 or above in all cartridges I shoot. I have a 6.5x284 that is ready for a new barrel. I was going to do a plain Jane 7x08, but now will look at your 7x47, but with 40 degree shoulder, min. taper.

 

[Aussie_bob]

The Reamer that John made for this case has 30deg shoulder and .010" taper in case he feels 35 deg would be the max he would go he has had 40 deg shoulders before in 7X57AI and others this is looking very good now that we have the velocity up and powder load is to the shoulder so close to 90%.base of boatTail would possably be touching the powder colum.

 

[NeilNE]

If I do this, it will be 40 degree with .010 taper. I single feed 90+ % of all my guns, except my one hunting rifle. The 7mm barrel I have will not shoot heave 7mm, because of the twist, so this might work for me. The other decision I will have to make is, after the above barrel is gone, will I be shoot heave 7mm bullets later on.

 

[NeilNE]

Aussie_bob, any updates???