Rifle: Win 70 Classic Super Express 24"
Primers: CCI 250
Powder: IMR4064
COL: Bullet seated to the first cannelure, 91.1mm (3.587")
Groups: 3 shots
Distance: 100m
Altitude: 1000m
Temperature: 25�C (sunny but windy)
Chronograph: PACT at 3m
charge vel sd es Group(mm) MOA
74 2351 14.9 29.8 40 1.37
75 2378 6.0 12.0 45 1.55
76 2414 20.7 41.5 57 1.96
77 2424 6.2 12.5 39 1.34
Although the groups were not exceptional, they are good enough for hunting. The results were very uniform. There were no signs of high pressure... Since I obtained over 2,400 f/s, I stopped at 77gr.
Has anyone experimented with this powder and with different seating depths with these bullets?
Antonio
------------------
Gerard Schultz
GS Custom Bullets
I did, and reported it on:
http://www.serveroptions.com/ubb/Forum16/HTML/000305.html
I don't remember if I reported it, but I used a Lee factory crimp. Given the similarity of IMR4895 and IMR4096 in this case, I don't understand why you did not get better groups. Did you get all previous fouling out of the barrel?
Does that rifle shoot well with other bullets?
The sd and es are bigger than I got with the surplus 4895, I wonder if that's a factor? I used WLR primers, don't know if that matters much, but I seem to
Gerard's printed directions say do one load progression to pick velocity (I chose 2450 fps), then vary the seating depth on that load to get best accuracy. I did not have to do that, but maybe you should try it?
Good luck,
Don
Gerard:
I am limited by magazine length to 91.5 mm OAL. I got only 38 bullets left, so I will experiment by varying seating depth with a couple of them around 77gr. I am content to shoot my next buff at 2425 f/s at a somewhat lower pressure.
So far, I think your bullets are great Gerard. They look awesome and considering my post-taliban finances, I am even considering robbing a bank to try them asap on a buff in Africa.
Q: Since your FN bullets do not have an ogive, what is really the effect on accuracy of varying seating-depth slightly, since the rifling will only engage the bullet at the first band?
Don:
The rifle was clean (Barnes CR-10). Exceptionally, I have shot in the past a few 3-groups with this rifle at 100m that went as low as 12mm (0.41 MOA) with Hornadys 400 gr RNSP and 7mm (0.24 MOA) with Barnes XFB 400gr. However, its (and my...) typical average performance off the bench with 5-groups at 100m has been between 1 and 2.0 MOA. I was envious of your group...
Thanks again, Antonio
------------------
Gerard Schultz
GS Custom Bullets
------------------
Ray Atkinson
Did you get the play in your bolt action figured out? I guess so if you are testing loads in the same 416.
BTW, I am assuming your bullet is the 380 grain FN. I didn't see bullet weight specified on my first perusal, but maybe CRS has struck again. Gerard also has a 410 grain FN and a 330 grain HV.
------------------
So many bovids! So little time and money!
RAB
Due to the immense difficulty in obtaining components over here, normally I do not like to get involved into too much group and velocity paranoia, but I will try Gerard�s suggestion to see if there is an improvement.
I have shot two buffalo, an elephant and 3 hippo with that rifle and its 1.5 MOA accuracy and they all died happily. When I learn how to manipulate photos I will post them...
RAB:
You are correct in that it is the same rifle (the only biggy I got). I have been with it to Africa 3 times and it has worked well so far.
I got basically two hypotheses on the rifle�s problem:
1) The coned section of either the action or the barrel is outside tolerances.
2) The locking lugs have been set back and there is headspace.
Since the rifle shoots well, and I do not shoot above maximum loads,and there have been no problems with case separations (I have been able to reload brass up to 8 times...), the most probable explanation is 1). The person who thought about 1) is a gunsmith who posts in HA and he said there was no major problem. That the solution was to take a turn off the barrel and rechamber, but that it was not really necessary.
I would like of course to have a gunsmith look into it if I knew one I can trust over here. There is not much experience with big-bores left in the gunsmith pool in Mexico.
Maybe next time I go to Africa I can have a gunsmith look into it in say Atlanta or Joburg...
Regards, Antonio
That is a great idea...!
As a matter of fact I have some shims, since I recently bought a kit with 12 sizes from Brownells that goes all the way to 0.001".
How could I proceed to simulate a go-no-go process?
Should I use a factory cartridge or empty brass and work up shims until the bolt does not close or should I use an empty cartridge fired in my chamber?
Regards, Antonio
1. - Remove Firing pin
2. - Chamber a new factory round with a .005" shim stuck to the boltface with vaseline or a light dielectric grease.
3. - Assuming full, unimpeded closer, chamber the same factory round with a second .005" shim stuck to the boltface.
4. - Repeat, slowly, with a third .005" shim and see how far the handle down without excessive force. Usually you will feel a "wipe" of resistance somewhere between the second and third .005" shim. If this occurs, back off to a .003" shim for the final shim and try again for full closer. As necessary, keep backing off your shim stack in .001" increments until the bolt closes with a nice firm feel. This is about all the headspace in "your" particular rifle.
I have the same rifle as yours, also in .416 Remington and it has .012" headspace as per this admittedly less than perfect method. I will not say if this is too much but I think it is not. Maybe John Ricks or someone else here can offer a better guess than I, on this.
So, It is my view that if your gun indicates
.012" to .015" clearance with this method it does not have a headspace problem. I have had a few SAKO and Remington rifles that showed .018 - .020" or a touch more and they seemed to function just fine with brass showing no sign of stretching.
[This message has been edited by Nickudu (edited 12-15-2001).]
I also don't know the spec on headspace for the 416.
I seem to remember that the NOGO gage on a 308 is +.004, the field gage is +.008.
You are not supposed to shoot a 308 with .008 or more headspace. I suspect that the .416 limits are about the same.
The case will never be maximum dimension either, so usuing your method .010 seems safe. .015 seems 'way too loose. The gages are only about $20 and are common for all belted cases, so in the US I'd just buy them. (I have a friend that has a set! )
Don
If you think that you have headspace, don't shoot that rifle, it could be dangerous and needs to go to a qualified gunsmith...
Barnyard check for gunsmithing...take off the extractor and take out the firing pin then cut a piece of electricians tape and stick it to the bolt face then close the action on a empty resized round, it should close easily, now try two layers, that should be very snug indeed, if not then you need some repair work done. It should not close on 3 layers...Of course you can force anything so don't do that.
A clue of head is firing a primer and see how far it backs out..but all this is barnyard stuff just to discover a problem exists...
------------------
Ray Atkinson
I wasn't trying to argue or correct you, just clarifying for any readers not working under an importation handicap.
I have found that most new Remingtons will close on a Field gage (+.008). (Even the supposedly high end ones.) Most new Brownings and Winchesters would close on the NOGO, but not on the Field.
Don
There are other real factors in this and one of the more prevalent is the variation of belt location. There is potential for anywhere from .003" - .005" variation between brands and even lots of the same brand. You can see how that might serve to confuse the issue.
------------------
Ray Atkinson