IMPORTANT:
Dont be a dumbass. Just because you're working with blanks doesnt mean you should'nt take all the safety steps that you would with live ammo. Blanks CAN be dangerous if you are careless and allow them to be. SAFETY begins and ends with YOU.This is something I dont reccomend sourcing out to a "Gunsmith" - as theres maybe 10 in the entire country that have a clue of what they're doing with Browning 30 Cal MG's, let alone the 1917a1. Even then, very few of them have experience working with blanks...
Proceed at your own risk. If you blow your gun up - its your problem, not mine.
Blank Adapting the M1917A1 Watercooled Machine Gun
Date Written: 10/17/11
Author: Chris Guska
Blank adapting the 1917 (A1) Water Cooled 30 Cal is slightly different than blank adapting the far more common M1919a4 Air Cooled 30 Cal. Many of the same basic steps and details apply, but there are a few nuances that I've found that make it worth while to detail separately.
This may seem like a rehash of Blank Adapting the M1919A4 - there are KEY differences with regards to the BFA and specifics around the gland packing.
I'll break this down into sections, as its not all about a "BFA" like it is with rifles.
1.) Selecting blanks (You are here)
2.) Feedway modifications
3.) BFA Construction
4.) Gland Packing
5.) Belts vs Links
6.) Feed parts
7.) Troubleshooting
1.) Blanks
The blanks you chose will impact most everything about the blank adapting process. There are a number of surplus and new made options available on the market which are and have been particularly popular with Browning 30 operators.
Surplus: These blanks are typically full length 308 blanks, with a long "bullet crimp". brass Austrian, British, Pakistani, and now plastic German blanks are available.
I consider these blanks to be preferable for use in Browning 30's due to consistency of overall length of the round as well as price.
I've landed on two different surplus 308 blanks that I've been able to acquire in volume at low price. This was a simple economics decision on my part, as it has been with many other owners. The second facet to this decision is consistency - as I really dont feel like dialing my piece into a new blank type for every battle, I want to set this thing up "once" and just run it till I exhaust my supply of blanks (high 10's of K's).
I currently ONLY run the POF headstamped brass 7.62x51 (308) "Pakistani" blanks that were available from Wideners and Century Arms in 2009-2010 in the units 1917a1. I've found these blanks to be extremely consistent, clean burning and "hot" charged- hot enough to consistently cycle the 1917a1 when packed and full of water.
I run the DAG / HK Green Plastic "platzpatronen" in the unit's 1919's. These are fairly consistent, and of sufficient power to cycle the 1919's. I havent messed around with these in the 1917A1. I suppose they'd probably work out pretty decent.
Commercial: New made 30.06 and 308 blanks are available from blank vendors such as Atlantic Wall Blanks, Nartron and Joe Swanson Movie Picture Blanks. These blank cartridges can come in a short or long crimp variety - and are typically fairly consistent in powder charge. I cannot comment on consistency of cartridge overall length.
308 vs 30.06?
The caliber you chose to run has an impact obviously on what barrel you have to use - but it will also require some attention to the bolt. A bolt marked 7.62 on top will run 308 or 30.06. A bolt that is not marked (not Israeli or Danish modified) "may not" be able to run 308, but you will need to check your blanks to the bolt.
The difference between the bolts is in the T slot that the cartridge slides down as the action operates. 308 cartridges are typically made with a different extraction groove than 30.06, where on an original unmodified WW2 production 1919a4 bolt - the 308 cartridge wont fit down the slot properly. Some 308 blank cartridges are made with the 30.06 style extraction groove and will work in "unmodified" bolts. Conversely, some "unmodified" bolts are so worn, that 308 cartridges will work without issue.
Photo of the T slot
Provided you have a "308" bolt in your gun with the modified T slot, you can run 30.06, 8mm or 308 with a simple barrel change and some minor tweaking.
** Notes about "Israeli" vs "GI" gun kits / builds. Basically, there are only 3 parts that have any impact on what calibers you can run in a Browning 30. With exception of those 3 parts, all of the other "Israeli" modifications have no bearing on being truly able to shoot "308" or any other caliber for that matter. A "USGI" "30 Cal" 1919 or 1917 can be made to shoot 308 blanks. More about this in Section 2: Feedway
Confused? Don't be. Chances are you most likely have a modified bolt and all of the above is just theoretical...
On to Part 2 - Feedway modifications
