Chamber adapters: They seem to be accurate

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TTv2

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I decided that I wanted the ability to shoot .22 Mag from a rifle, but didn't want to buy a new rifle and figured for under $30 an adapter for .223 was worth trying. In the same order I also got a .30 Carbine for .308 and haven't been able to try that yet, don't have ammo, but after seeing the result of .22 Mag from .223, I'm sure the accuracy will be as good.

So, how was the accuracy? I was shooting at 15 yards using a wood block as a rest and it usually took two strikes on the rimfire primer to fire, so the couple times it fired on the first strike I got in the habit of not using my best trigger pulls and they turned into flyers. Flyers aside, the group was the size of a quarter. The POI was well below the bullseye, I expected that, but windage was about dead on.

1.jpg

So, is this something that is great for 50y headshots on anything? No, this is not a long range solution, not unless you had some way of having a second zero for a scope or you knew your holdover for a certain distance.

What use do these things have? Harvesting small game at close range, I'd like to see a .308 not blow up a rabbit at 10y or a .223 a squirrel at 15y. A second caliber option in the event you can't get ammo for the rifle or you can only find a certain ammo (.32 is one people are saying is available right now.)

That said, I do not recommend the .22 rimfire adapters because there's the issue of not firing on the first strike, but also the firing pin plug that is needed to fire them is easy to lose and without the plug you cannot shoot them.

I will recommend the .30 Carbine and .32 adapters because they don't require a plug to shoot them like the rimfires do, so you don't have to deal with losing a plug and it should also fire reliably on the first strike. I don't know that for a fact yet and it may just be my rifles causing the issue, but I will report back on the results for centerfire when I can get some .30 Carbine to shoot.

Also, I do want to say that I think rifles chambered for rimmed cartridges like .303, .30-30, 7.62x54r, .30-40 are better choices over rimless ones because the rim is a more positive headspace. By that I mean the manufacturer of these adapters doesn't know your specific rifle's chamber, so with the rimless adapters there's a chance the adapter will not sit deep enough in the chamber and not allow the bolt or the break action to close or will sit too deep and the firing pin won't hit the primer. Not saying that this is a guarantee, I haven't had this issue yet, but it is more difficult to close my break open rifle with the .22 Mag adapter while the shotgun adapters I have are no issue at all and those headspace off a rim.

EDIT: Adapter was bought from MCA Sports. I think they're the only company that makes rifle chamber adapters.
 
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Thanks for the write up, I've always wondered how well the inserts worked.

Is it a problem to remove the empty from the insert, or the insert from the gun? Could we please get a photo of the rimfire firing pin plug, as I'm not understanding exactly how that works?
 
I have a .32 ACP to .308 Winchester adapter from MC Ace, that I've used in my Ruger GSR at close range.

One thing to note is my chamber adapter was cut for the USA spec'd .32 ACP, which has a thinner rim than Euro spec'd .32 ACP. Being that .32 ACP is a semi-rimmed cartridge, I couldn't close the bolt on my Ruger with Euro spec'd ammo until I "adjusted" the adapter's head spacing on the .32 side of the adapter.

I made a lapping tool from an allen screw and a spent casing, then used J&B bore paste (what I had on hand) while turning that tool into the adapter until it deepened the .32 ACP rim pocket of the adapter enough for Euro ammo.

I've only tried this .32 ACP in the GSR at 15 yards. The bullets strike about 1" to 1.5" below point of aim at that range, per my old records. One has to consider sight line height above the bore and the range a .308 is normally sighted in.

Now I'm tempted to shoot a few "volleys" of .32 ACP out of the GSR today, since it looks like I have an easy work day. ;)

Some old pics below of the Euro ammo rim sitting "proud" of the adapter, the lapping tool, and some fired cartridges.

View attachment 973901

View attachment 973902

View attachment 973903
 
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I decided that I wanted the ability to shoot .22 Mag from a rifle, but didn't want to buy a new rifle and figured for under $30 an adapter for .223 was worth trying.

So, how was the accuracy? I was shooting at 15 yards using a wood block as a rest and it usually took two strikes on the rimfire primer to fire, so the couple times it fired on the first strike I got in the habit of not using my best trigger pulls and they turned into flyers. Flyers aside, the group was the size of a quarter. The POI was well below the bullseye, I expected that, but windage was about dead on.

What gun were you using?
 
TTvP2 -- could you post a photo of your .223 adapter and tell us where you acquired it, please? There are a couple of different approaches to where the adapted cartridge's bullet is positioned within the chamber. I'd be interested in pursuing the same combination you used.

3072_155_214-special-shot-wounds.jpg 22LRCapin257Roberts01.jpg

In another posting I discussed using .32 S&W Long-to-.303 British chamber adapers from GPC in both my P-14 and 'Jungled' No.4 LE.

https://www.gunpartscorp.com/products/197660

I was getting pretty good groups at 25 yards using HBWC handloads:
LE No.4 Mk.I Jungled.jpg numrichstock.jpg 303ChamberAdaptors.jpg WadcutterWAdapter.jpg

p14target.jpg

Actual .32 ACP ammo didn't group anywhere near as well. I think the longer case + HBWC bullet minimizes yaw through the unrifled portion of the adapter, unlike the short .32 FMJ RN which can rattle around a bit before engaging the rifling.

I'm on backorder at the Shooters Box for a similar adapter for my Mosin carbine:

https://www.theshootersbox.com/762x...ter--Chamber-Reducer--Stainless-_p_52516.html

BTW, the reason I've been playing with these is that they allow me to shoot some of my milsurp rifles cheaply and conveniently at my indoor pistol range.
 
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I have a McAce .32ACP/ .308 I have used in a Savage 110, but only on paper at 25 yards , just over an inch groups CtC. Mine worked with both Silvertips and some Geco Hardball just fine and averaged about 1155 over my chrono with either.

If I can find the darned thing I have a McAce .22LR/. 223 SOMEPLACE I want to try with the Aguila 60 grain Subsonic in 1-7 and 1-10 twist rifles.

-kBob
 
I had a few moments to spare today, so I gave the .32 ACP* another go-round out of the GSR.

The biggest problem for me is I have to aim at the top of the black dots to compensate for the point of impact. Which means the front sight post completely obscures the black dots for me. Not to mention the fact that front sights are simply blurry to me at 55 years of age, even if using an aperture in the rear. I should've used an optic, but . . .

Those black dots measure 21 mm at the outside diameter of the 8 ring. All shots fired from prone at a measly 15 yards using my elbows on the ground. I couldn't see those target dots well enough for consistent hits, yet the ghastly miss at the top left was me jerking the trigger which is why it went above point of aim.

While shooting a rimfire gun is the better way to go here, shooting guns on a nice day is better than not shooting guns. :evil:

View attachment 973997

*Fiocchi FMJ and S&B FMJ
 
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I decided that I wanted the ability to shoot .22 Mag from a rifle, but didn't want to buy a new rifle and figured for under $30 an adapter for .223 was worth trying. In the same order I also got a .30 Carbine for .308 and haven't been able to try that yet, don't have ammo, but after seeing the result of .22 Mag from .223, I'm sure the accuracy will be as good.

So, how was the accuracy? I was shooting at 15 yards using a wood block as a rest and it usually took two strikes on the rimfire primer to fire, so the couple times it fired on the first strike I got in the habit of not using my best trigger pulls and they turned into flyers. Flyers aside, the group was the size of a quarter. The POI was well below the bullseye, I expected that, but windage was about dead on.

View attachment 973870

So, is this something that is great for 50y headshots on anything? No, this is not a long range solution, not unless you had some way of having a second zero for a scope or you knew your holdover for a certain distance.

What use do these things have? Harvesting small game at close range, I'd like to see a .308 not blow up a rabbit at 10y or a .223 a squirrel at 15y. A second caliber option in the event you can't get ammo for the rifle or you can only find a certain ammo (.32 is one people are saying is available right now.)

That said, I do not recommend the .22 rimfire adapters because there's the issue of not firing on the first strike, but also the firing pin plug that is needed to fire them is easy to lose and without the plug you cannot shoot them.

I will recommend the .30 Carbine and .32 adapters because they don't require a plug to shoot them like the rimfires do, so you don't have to deal with losing a plug and it should also fire reliably on the first strike. I don't know that for a fact yet and it may just be my rifles causing the issue, but I will report back on the results for centerfire when I can get some .30 Carbine to shoot.

Also, I do want to say that I think rifles chambered for rimmed cartridges like .303, .30-30, 7.62x54r, .30-40 are better choices over rimless ones because the rim is a more positive headspace. By that I mean the manufacturer of these adapters doesn't know your specific rifle's chamber, so with the rimless adapters there's a chance the adapter will not sit deep enough in the chamber and not allow the bolt or the break action to close or will sit too deep and the firing pin won't hit the primer. Not saying that this is a guarantee, I haven't had this issue yet, but it is more difficult to close my break open rifle with the .22 Mag adapter while the shotgun adapters I have are no issue at all and those headspace off a rim.


Who is the manufacturer of the adapters? I did not see it mentioned in the OP. Wanting to possibly order some myself.
 
Thanks for the write up, I've always wondered how well the inserts worked.

Is it a problem to remove the empty from the insert, or the insert from the gun? Could we please get a photo of the rimfire firing pin plug, as I'm not understanding exactly how that works?
It may be more difficult with .30 Carbine and .32 Mag, but .22 Mag I just tapped the adapter on the table and the case came out easy enough. As for removing adapter from the chamber, I'd say it's too easy, my ejector would spit the adapter out and I'd have to look for it when I'd forget I need to stop the adapter from flying out.

Will upload a picture of the plug later.
 
As for removing adapter from the chamber, I'd say it's too easy, my ejector would spit the adapter out and I'd have to look for it when I'd forget I need to stop the adapter from flying out.

I had a Winchester 37A with an ejector instead of an extractor. That thing threw out live or dead rounds far, far away.
 
I had a Winchester 37A with an ejector instead of an extractor. That thing threw out live or dead rounds far, far away.
Which is why I am not recommending rimfire adapters, I think these things work best with centerfire calibers anyway.
 
I had a few moments to spare today, so I gave the .32 ACP* another go-round out of the GSR.

The biggest problem for me is I have to aim at the top of the black dots to compensate for the point of impact. Which means the front sight post completely obscures the black dots for me. Not to mention the fact that front sights are simply blurry to me at 55 years of age, even if using an aperture in the rear. I should've used an optic, but . . .

Those black dots measure 21 mm at the outside diameter of the 8 ring. All shots fired from prone at a measly 15 yards using my elbows on the ground. I couldn't see those target dots well enough for consistent hits, yet the ghastly miss at the top left was me jerking the trigger which is why it went above point of aim.

While shooting a rimfire gun is the better way to go here, shooting guns on a nice day is better than not shooting guns. :evil:

View attachment 973997

*Fiocchi FMJ and S&B FMJ
Similar issue I'm having with the shotgun adapter, the POI is far off the POA and I think this is a systemic issue with all rifle adapters and some shotgun adapters. However, I'm seeing evidence that .45-70 in shotgun adapters is capable of hitting POA given the vast bullet weights from 250 to 500 grains. This is a rifle adapter discussion tho, so I'd like to keep it to that.

I have an advantage tho with the H&R rifle because both my .222 and .308 barrels have scopes mounted to them, so I'm getting much better consistent sighting shot to shot over iron sights of milsurp rifles everyone else is using and I do think .32 ACP is not a good fit accuracy wise for these adapters given the differences of US and Euro ammo, also I find that with .32 guns they prefer a bullet over 90 grains, so I feel the heavier .32 S&W or H&R bullets will shoot better in an adapter for a rifle than .32 ACP will.

.30 Carbine I have no idea, never seen anywhere that anyone has ever done .30 Carb in an adapter.
 
Cast bullets with light loads are another good option for small game with center fire rifles.
 
The biggest problem for me is I have to aim at the top of the black dots to compensate for the point of impact. Which means the front sight post completely obscures the black dots for me.

The milsurp open sights I've tried shoot pretty well using inserts -- these rifles all tend to be sighted for a minimum of 2-300 yards with service ammo, so the light pistol loads often end up dead-on at 25 yards or so.

Not to mention the fact that front sights are simply blurry to me at 55 years of age, even if using an aperture in the rear.

Same here, hence the shooting glasses in my avatar. I bought them so I could aim a Gewehr 98 properly with the tiny notch on that stupid roller coaster rear sight. The adjustible aperture behind the RX lens has to be stopped all the way down for me to focus properly on open sights these days. Aperture sights usually work just fine without correction though, provided the peep is close enough to my eye.
 
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