Springfield XD Forum banner

21 - 40 of 42 Posts

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #21
I was up at Alex Pro Firearms (APF) the other day, nearly popped on one of their 16” .45 Carbines...under $1k, and really nice guys...they said that they don’t have issues with them, but if they do...bring it in, they make it right, whatever it takes.

Yeah, it’s blowback, but...it just might be the way I go. I kinda like the idea of only being an hour away from them.

PS: they make a 10mm...
Pretty nice... I go on about blowback, but I don't have any real experience. I could be Maki g mountains out of mole hills. Yes it has more recoil... But I bet it's still more managable/accurate/faster than a real pistol. So then what does it matter?
 

·
Registered
Joined
·
23 Posts
Blowback's not too bad. But I am a fan of CCMG's radial design. It's definitely the optimal decision. My AR 9mm is blowback. With blitzkrieg's buffer set up, it shoots pretty well and the recoil is extremely manageable.
 

·
Registered
Joined
·
19,918 Posts
Pretty nice... I go on about blowback, but I don't have any real experience. I could be Maki g mountains out of mole hills. Yes it has more recoil... But I bet it's still more managable/accurate/faster than a real pistol. So then what does it matter?
You are. Blowback isn't that bad.

The answer you really seek though is a Draco with a brace. Cheap ammo, high capacity and all that intermediate range and power.

Good mags are getting more and more expensive though. Plenty of cheap range mags out there however!

 

·
Registered
Joined
·
23 Posts
You are. Blowback isn't that bad.

The answer you really seek though is a Draco with a brace. Cheap ammo, high capacity and all that intermediate range and power.

Good mags are getting more and more expensive though. Plenty of cheap range mags out there however!

I really like your taste.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #25
So holidays have delayed stuff... CS said my bolt didn't look exactly normal. They said they sent up to engineering. Didn't hear back so I asked where it's at... Said not totally bad... But they are going to replace my bolt anyway. I assume one will be showing up and I'll send that one back. Can't complain about any of that....
 

·
Registered
Joined
·
3,173 Posts
After all of mods and changes, this has become an expensive weapon. I’ll stick with what I have.

My son and I have a 300 Blackout. He has had good success on hogs with a suppressor in Texas.

Ballistically while the 10mm has merit, the 300 Blackout works better for me.

However, my concern is mixing 300 Blackout rounds in my 5.56 AR.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #27
I would never confuse 10mm for 300. You would never confuse 300 prices with 10mm.

CMMG actually sent me 2 bolts. I'm a little conflicted, certainly their mistake. Been too busy playing with knives to get to the range and see how the new bolt does. It is a very compact package with great ergos. I dig it.
 

·
Registered
Joined
·
1,235 Posts
I would never confuse 10mm for 300. You would never confuse 300 prices with 10mm.

CMMG actually sent me 2 bolts. I'm a little conflicted, certainly their mistake. Been too busy playing with knives to get to the range and see how the new bolt does. It is a very compact package with great ergos. I dig it.
Two separate packages? If they were in the same package, I doubt it was a mistake.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #29
I got the replacement a week or two ago. One showed up on my doorstep yesterday. Like Christmas in January...
 

·
Registered
Joined
·
1,235 Posts
I got the replacement a week or two ago. One showed up on my doorstep yesterday. Like Christmas in January...
Ah, well, that could have been a mistake then, lol. Shoot them a message, they'll probably have you hang on to it, and you'll be one of their stand-up customers ;)
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #31
OK... So got to the range... I shot 150, finally zeroed my MRO and laser. I used the ranges sled and spotting scope... Kinda cool putting the laser on bullseye and pulling trigger next to you while you watch in scope. :)

Acurate enough at 25.



20200123_190544.jpg


Center is a box rapid fire by me at 25.

20200123_190550.jpg


I'm no Dead Shot, but I can put rounds on target relatively fast. Like I've said, it's not bad, it's just not as easy to keep on target as the MP.

So... Check my lugs on the bolt. After 150,looks similar to last bolt. I'll stop worrying about it and just shoot it...

Except... I'm going along, sighting in, brass is bouncing on to table.... Ummm F' ME...

20200123_194618.jpg

Ummm... No, the pictures do not make them look worse... They look worse in person.


20200123_194718.jpg

20200123_194759.jpg

20200123_194812.jpg

There was just a couple, out of the whole session that looked minor like above. The rest were seriously bulged... I kept shooting cause it was on a sled, but it did not give me a warm fuzzy to say the least. This was new Sig ammo. I had nothing else to check different brand.

So next trip, I am swapping out bolts. I'll take some Underwood to see if it's the same. But again that kinda gives me the Willie's, and I certainly would not reload no matter what a resizing did. Of course... It ran great.
 

·
Registered
Joined
·
1,235 Posts
That's a lot of bulging.

Like you said, try some other ammo, but kinda looks like further discussion with CMMG is in your future.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #36
The chamber itself has about 3mm at the end that are maybe a couple thousands open. The cartridge base is at the end of the chamber, and base/rim sticks out to the bolt. So the full case is supported by barrel, minus a few thousandths at the end. Why that's there I don't know... Extraction aid, feed? But normally, if the case formed to chamber, it would look like my first cases with a very slight bulge.

I ran out of time before work, I need to see if my badly bulged cases fit it the chamber. I can't imagine they do. If they do, then they are forming to the chamber and maybe Sig is a little off and not so bad because the chamber is still containing.

If they don't, then that could be early opening/extracting... Which of course would be much much worse. But I can't really imagine that's happening. My bt is new, so in spec. The delay is enough for bullet to leave the barrel, and breech to open after pressure has lowered to safe. Opening so fast would be like direct blowback, and it not having enough weight to delay opening. So ya, I can't really see the problem being that drastic. It's just pretty odd.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #37
OK... So searching around, and a thread on AR that is still going that I've read before... A poster C&P'ed CMMG's response to him with similar concerns on excessive bulging. They replaced his barrel, but this was their response:

I am sorry this response has taken so long, but I wanted to ensure due diligence when it comes to the safety of our customers. I personally coordinated testing and validation with CMMG's Product Design Engineers when we received several customers who were concerned with what appears to be 10mm cases bulging. CMMG, Inc. take this very seriously as we had not experienced true case bulging in any of our durability or function testing prior to releasing this firearm. I do want to assure you that the results of the additional testing concern that your Mk10 firearm is safe and reliable. We removed the barrel in question off of your Mk10 and replaced with a new barrel when it arrived. We did our testing using a CMMG owned lower and multiple barrels from different batches. Our initial testing pre-launch focused on big name manufacturers of 10mm ammunition (Winchester, Federal, S&B, Sig, Hornady, etc.) who had offerings in the most common grains, specifically 180gr and 200gr. With this new testing we ordered new lots of ammo from the original test ammo manufacturers and over 20 different types of ammunition from smaller manufacturers, and in offerings outside of the 180gr & 200gr. We created the statement below based on that testing. What you were seeing on the casing was not bulging, but case swell. Bulging would be where the casing grows in length and the material thins in an area, which typically leads to a ruptured case. Case swelling is what happens to all ammunition when it is fired and it forms to the chamber. Due to the design of the 10mm casing many of the cases appear to be bulging due to the brass filling our chamber lead. With our Radial Delayed Blowback (RDB) our bolt is locked into place when the round is fired and the delayed unlocking ensures safe operation. When the brass is manufactured correctly and the loads are not pushes to the hot side, then this case swell into the chamber lead does not appear.

As I stated above, your firearm has been verified as safe. Choosing a US manufacturer of ammunition in the 1,050 1,275fps will minimize the case swelling on the Mk10 10mm. We had concerns about very hot offerings in 10mm from hand loaders and some smaller but reputable manufacturers. The casings we were provided were a mixture of DoubleTap and Sig Sauer. We were not able to replicate the case swelling to match the spent cases provided. If these were reloads, that could account for the amount of swelling. We are including some of our spent cases with the firearm. When the casing is unchanged, but is used to contain 10mm rounds pushing 1,300fps or greater, then our firearm is still safe. The safety comes from being built around the AR platform barrel, barrel extension, bolt, and RDB delayed unlocking. Unfortunately, bad things happen to casings when anyone chooses to push ammunition beyond the design intent of the casing.

CMMG, Inc. Statement:

CMMG recognizes that the chamber lead and chamber in the Mk10 result in a less than 100% fully supported casing. Handguns do not have the same lead or chamber design due to the short distance and the way the round chambers with the barrels tipping/moving to assist, yet many 10mm handguns have unsupported cases also. The Mk10 chamber and lead were designed in a way to provide the most reliable feeding behavior while maintaining safe operation with properly loaded 10mm ammunition. The chamber and leads used to manufacture the Mk10 are similar to those we use on the 9mm, 40S&W, and .45ACP. With these calibers we do not see any bulging with any factory offerings of +P or below ammunition. Unfortunately, 10mm was designed in a way that pressures generated by max loads cannot be well contained in an unsupported chamber, resulting in case swelling and the inability to reload cases with certain combinations. Not every 10mm case is the same. SAAMI only defines the external dimensions of cases, which leads to varying wall thicknesses and strength. We've measured as much as a 25% difference in wall thickness between manufacturers.

CMMG has fired tens of thousands of rounds through our Mk10 platform durability testing and found no safety concerns from the case swelling. During our function and reliability testing, which tests feeding, extraction, ejection, and durability, we tested a wide variety of ammunition. We found that when the Power Factor > 230, using 180gr bullets, the greater the likelihood the casing will show visible signs of "bulging". CMMG concluded that the firearm was still safe, as it is designed to function and contain the pressures of properly loaded 10mm ammunition safely. CMMG does not recommend continuing to shoot ammunition that shows multiple signs of overpressure. If you are seeing extreme case swelling and any other common sign of overpressure, such as ejector swipes, blown primers, split cases, etc., discontinue using that ammunition and test another load or brand. CMMG stands behinds its products and is confident in our design of safe and functional firearms. In this case, we have found the inherent design of the 10mm cartridge produces some tradeoffs when it comes to the ability to reuse and reload cases. Once again, we would like to thank you for your business and hopefully this brief explanation might help you better understand our position on this particular situation.

Thank you for your understanding and patience in this matter. We took this claim very seriously and only had the safety of our customers at heart. Have a terrific New Year and a blessed day.
 

·
Premium Member
Joined
·
15,508 Posts
Discussion Starter #39
Interesting...

Not sure if I’d feel better or not.
Certainly makes sense from what I posted... But ya... And most 10mm fans reload... And no way in hell I would reload any of that.
 

·
Registered
Joined
·
1,235 Posts
"Doc, my arm hurts when I do this"
"Don't do that"

Yeah, I wouldn't reload any of that either, but I also see their point. I don't know of any manufacturers that care about the reloadability of the fired case.
 
21 - 40 of 42 Posts
Top