Model 1 Sales 300 whisper upper function problems

[jripper]

Update:

I think I have this thing figured out. It will run reliably with 220 and 240 graind Sierra's, subonic. Put 20 rounds of 11 gr. AA 1680 and 220 Sierra bullet through last Sunday, and ejection was quite positive. Did not chronograph, but they were very quiet, and almost had to be subsonics. I did chrono the 240s with 10.3 g AA1680, and they were only going 850 fps (they did run, however).

The bolt has broken in, and works a lot smoother.

I am still using a full length stock and buffer tube, and have my JP gas block wide open.

Runs good with all supersonics that I have put through it.

Here is what I have concluded about this gun/round.

Bolt needs to be broke in fully (good tip, Quarterbore)

Gas port needs to be .120 or slightly larger.

Need to use slower powders within the reccomended range for this cartridge, to make it run with subsonics.

I didn't really mind the experimenting, as it has occupied me during the winter.

I still would reccomend the upper, with qualifications concerning what is necessary to make it run.

It is an economical way to get into the cartridge.

If anyone buys one, I would reccomend getting a upper without a bolt, and buying a chrome plated bolt from someplace else, however.

Joel

[sharpshooter33]

Originally Posted by jripper

Update:

I think I have this thing figured out. It will run reliably with 220 and 240 graind Sierra's, subonic. Put 20 rounds of 11 gr. AA 1680 and 220 Sierra bullet through last Sunday, and ejection was quite positive. Did not chronograph, but they were very quiet, and almost had to be subsonics. I did chrono the 240s with 10.3 g AA1680, and they were only going 850 fps (they did run, however).

jripper,
What primer are you using? I was looking at my Sierra book for pistol loads for the 300Whisper and it looks like there using Federal 250M which I think is a magnum pistol primer???? and they are using 11.7gr AA1680 in a Contender 10" to get 1000fps. Have you had a chance to Chrono the 11.0gr 220gr SMK load yet? I just worked up some 220gr SMK with 11.0gr AA1680 and CCI 400 SR primers. Let you guys know how they do on Friday. Don't have access to a Chrono so I won't be able to report on that.

SS33

[jripper]

No, I have not chronograph that load. I will probably do that this week. I believe I was using federal small rifle primers (standard, not magnum).
It burns every bit of powder, and I don't think a magnum primer is going to make much difference.

Right now, I have been going by sound and feel, and it would appear to be subsonic, but I'll Chrono to check.

I don't know about the rest of you, but I am seeing a lot of variation from listed loads, vs. what I am getting from my own gun.

I have also seen a lot of variance on what different people are calling a maximum load.

For instance, I am using 18.5 grains W296 behind a 125 rem. psp. Some people list a max load of over 21 grains. Past 18.5, I am blowing primers out of the cases!!!

I guess that it what can happen when working with a semi-wildcat.

Joel

[sharpshooter33]

Ok I've been tinkering with my 300/221 for awhile now. I have a load that duplicates the Corbon 220 Subsonics on paper, but does function my action. I'm using 11.0 gr of AA-1680. With my setup cases/primer/seat depth etc... I'm getting the same sight settings on the Corbon 220subsonics as I am with my 220gr subsonic reloads. The difference is mine cycle the action.

My AR cycled fine with lockouts on my last round. My problem and question is....That it failed to extract on several cases. I've examined the extractor and it looks fine. Unknown if the spring is strong enough or not though. The second possibility could be that the action is trying to pull the casing out before the pressure has went down (or the bullet has left the barrel)

Has anyone else experienced this problem?

I'm shooting a 300/221 M1S 16" barrel, CAR length AGT full open and with full size stock and buffer setup. Is there any signs that I can look for to indicate which it may be?

I'm going to replace the extractor spring 1st then if that doesn't work I'm going to be clueless.

I did notice that I could hear the bullet impact at 100yards and also on the recoil I could see the bullet right before it struck the target at 100yrds. That was funny. I was using the Corbons and single feeding them. I even let a friend watch it through the scope on a couple of rounds. It didn't leave oblong holes. The bullet was stabalizing. I don't have a Chrono, but I would say they are in the 850-1000fps range.

Anybody have any input I would appreciate some thoughts on this one

[rednek58]

I know two things that might help you with the failure to extract. D-Fender brand ring that fits around the extractor spring, also a heavy Wolff extractor should help. Either one alone might work, but I have used them together with good results. Hope this helps.

[300whisper_newbie]

Good to hear Jripper! I've just finished loading up about 100 rounds of 11gr h110 with 220 sierras on top. Hopefully I'll get a chance to run them through my upper this weekend. If they don't eject I'll pick up some AA1680 and see how that works.

Thanks for the info!

--Chris

[mtb8r3]

Let me know how that load works in your gun. As I mentioned eariler, 11g of H110 with a 200 gr Gameking had VERY bad pressure signs. The brass I attempted to reload would not even hold a new primer. I finally settled on 10.2g for reliable operation, though I still need to chrono it.

[300whisper_newbie]

Originally Posted by mtb8r3

Let me know how that load works in your gun. As I mentioned eariler, 11g of H110 with a 200 gr Gameking had VERY bad pressure signs. The brass I attempted to reload would not even hold a new primer. I finally settled on 10.2g for reliable operation, though I still need to chrono it.

Don't tell me that, guess I better watch for pressure signs on my 220s, would hate get a KB so early in the game :( What was your parent case? I was told that using 223 parent cases reduces the internal volume slightly which is why I used the 221 fireball brass. That could explain why you would be getting pressure signs early. I used 10g h110 with 220 SMKs and didn't see any pressure signs at all so far.

--Chris

[jripper]

Just for information, I went up to 12.0 grains W296 with 240s, and pressures were fine. It is very similar to H110. I can't remeber which brass I used. I guess each gun is different, as towards maximum loads.

[mtb8r3]

Sorry for the delay...
Yes, I was using .223 LC brass cut down. 10 gr with 210 Berger’s showed no pressure signs, but 10.2g was just beginning to flatten the primer (Winchester). You may be correct about case volume. If you get the chance, send me an average case measure of grains of water and I will post a comparison. The 10.2 gr load will eject, but not chamber another round. I am thinking that a slightly slower powder may be in order.

Now that I have had some time (and weather) to do some more testing, my 185 Lapua moly load with 10.2 g H110 is shooting 1" 10 shot groups at 100.