"Inland" Manufacturing M1 Carbines - 1st hand experience

[pcaine]

I took a look at the bolt and observed what could be a spot of peening and some scoring on the lug. To my mind at 600 rounds, if this continues, there could be a short life cycle for this bolt, but I am not sure how much. I wonder how long do bolts live? I plan a shoot this Friday and I will compare the wear between the two look-sees.

I'm not experienced in making this kind of judgment, but just to get some bolt comparison I took a look at my Universal bolt with about 200 rounds through it. The Universal bolt hardly shows any wear at all. This makes the new-Inland bolt worthy of further attention and if need be repair or replacement. It is good to hear that Inland is helpful in this regard.

One last concern, I had a difficult time removing and replacing the slide to the barrel and receiver group. It finally came off and went back on, but I am not sure I know how to repeat the process smoothly. And some of the edges that fit together in this process look and feel sharp or even chipped. (I have a pair of jewelers glasses that allow me to do knee surgery on ants which I use to look closely at parts. Just doing so with these magnifying glasses makes things look worse than they are).

My earlier concerns about the sights and slide lock are resolved favorably. My problem in handling. They work fine now that I am more skilled.

Still I am favorably inclined to my new Inland, and I am positive in working out my concerns.

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Sleeplessnashadow]

The GI standard for hardening of the bolt was RC 38-43 with a second hardening of the rear of the bolt at RC 48-54. I have yet to see a commercial bolt with the rear hardened to GI standard. The ones I've tested have consistently been the same hardness front and rear. The hardness at the rear is mated to the GI standard for hardening of the hammer, 57-58 RC.

The GI hardness standards for the .30 caliber carbines were to ensure a part met a minimum life requirement measured in the number of rounds fired. The carbine's round bolt minimum was 3000 rounds fired continuously on fully automatic before the bolt failed. Most parts for the .30 caliber carbines have proven a life expectancy well beyond these minimums. Bolts manufactured during WWII and used to varying degrees during and after WWII commonly show no damage whatsoever. There are some variables at play in the lifespan of a bolt that include the various cartridges and powder loads used and the hardness/condition of the parts that come in contact with the bolt.

Every part on everything, us included, has a lifespan. Some are obviously shorter than others by intent, neglect, accidents, etc.

I have advocated occasional monitoring of the rear of commercial bolts to ensure the wear does not negate the safety design of the rear of the bolt that prevents the hammer from striking the firing pin before the bolt has rotated and locked into position for firing. Make it a standard inspection when cleaning the carbine. Over the years many commercial carbines with commercial bolts have been paired with GI hammers. This isn't unsafe, just expect this to shorten the lifespan of the rear of the bolt with continued use.

Specific to the bolts being used by Inland Manufacturing in their new commercial carbines, this inspection of the bolt should include the checking the condition of the right bolt lug after every 200-250 rounds. The manufacturer claims of the hardness have not matched those I have tested, but they don't require hardness testing to see if they were hardened properly. You'll see it for yourself if you know to look periodically. The softer it is, the faster and more pronounced the damage to the bolt will be. Measured in the number of rounds fired. nland bolts have typically shown damage at less than 1000 rounds. Some have shown it when sold new, from the test firing by the manufacturer. Photos of this have been posted earlier in this thread. The problem is most people don't know they need to monitor the condition of the right bolt lug and to do so requires removing the bolt from the slide that masks the surfaces of the right bolt lug.

Why this has happened and continues to happen, when Inland claims to have corrected this issue, I leave to Inland. Some of the bolts have marks left by the RC test on the right bolt lug, so they were tested. I've hardness tested some of these and they have been consistent at 30-32 RC.

Replacing the Inland bolt with a GI bolt, the action may or may not work. Some do, some don't. Due to variations in manufacturing that do not maintain the standards required by a GI bolt. Replacing it with another commercial bolt also may or may not work. Replacing it with another Inland bolt, monitor it for the same life span issues.

There is another option for a replacement bolt that will work with the commercial Inland carbines. Absent the short life span of the Inland bolts.

Inland's bolts have several small characteristics that are unique to their bolts and present only on one other, the bolts being used by Auto Ordnance. Inland has been clear they use many of the same sources for their parts as those used by Auto Ordnance. Both bolts share the same machining and dimensional differences that make them identifiable from all other bolts. The Inland bolts are round, the AO bolts are flat, the difference being aesthetic instead of function, strength or lifespan. Where the two part paths is their hardening. AO bolts I've tested and used have been consistent with proper hardening. When swapping bolts with the Inland bolts the AO bolts have consistently worked.

Last time I checked Inland's online store sells flat bolts. I haven't purchased and tested any of these. I have purchased extra AO bolts from AO's online store for testing on a number of occasions. They are less expensive than those sold by Inland. Personally, if I replaced a commercial Inland bolt I would do it with one sold by AO.

If you buy either an Inland or an Auto Ordnance carbine, check to make sure the gas piston nut is tight and stays that way. Stake marks or no stake marks, check the tightness. Both use barrels made by Green Mountain but this isn't a barrel issue, it's an issue with improper staking of the gas piston nut and both Inland and AO carbines continue to exhibit this issue.

Jim