Playing around with my ProChrono DLX and Strelok ballistic software using my FWB124.
Need the barrel twist rate for the Strelok app.
I'm wondering if there is a "generic" number that can be used, especially considering air rifles and the closer distances that we shoot.
Thanks !
I seem to remember most LW and other barrels being around 1:16" or 1:17" twist. Not certain on the FWB.
You can come reasonably close by measuring it yourself with a cleaning rod that has a free turning handle and some masking tape. Take about an inch piece of masking tape and fold it over the cleaning rod to make a sort of "flag". Make sure you do this so that you have plenty of clear rod to go the length of your barrel, if needed. Now use a snug fitting patch and slowly push it thru the barrel while watching the "flag" and when it makes a complete turn stop. Now take another piece of tape and mark that point on the rod where it enters the barrel, then remove the rod and measure from the barrel side of the tape to the end of the rod. If you have 16" then you have a reasonable idea that your barrel has a 1:16" twist rate.
On the other hand, if your barrel isn't long enough to get a full turn of the "flag" then watch for it to make half a turn and stop and mark the rod. Then by measuring from that point to the end of the rod and doubling it you can get the approximate twist rate. In other words, if the "flag" takes 9" to make half a turn then you can figure it would be close to a 1:18" twist rate.
@jim-in-swmo Thanks Jim... I had thought about doing that.
I actually have a nice Beeman deluxe rifle cleaning kit (cat# 9082 according to my old Beeman catalog) that I got when I bought my .20 HW77K from an estate sale years ago.
I've never used it, and pretty sure the rod rotates and the kit is complete all stored in the original box.
I use a crown-saver flexible pull-thru for cleaning my barrels.
Just got to find where I stored it away for safe keeping !
You're quite welcome, Ken. ?
As for your cleaning kit, I hope it hasn't been put somewhere as safe as some things that I've put "safely" away because if it has you may not find it! ? LOL!!
Well the Beeman barrel cleaner is very flimsy with a rod 1/8" in diameter... it ended up bending a bit, and when I went to straighten it, it broke off... now I have a very nice Tigerwood (?) handle... I will find a use for it, might make for a nice file handle.
I had another rod that is for airguns and .22 firearm barrel... the rod is thicker at 5/32" (coated steel)... I only use it for my firearm .22's, which I have not sure in many years... I used the clean mop which fit pretty tight instead of a jag and cleaning patch.
I had to use the "half way" flag, which gave me 9 1/2 inches... so the twist rate must be 1:19".
Well that's a bummer. Sorry to hear that your Beeman cleaning rod wasn't up to the task. That's one of the downsides to .177, the cleaning accessories can be a bit on the fragile side. Glad you were able to get an idea of the twist rate in your 124 barrel, though. Hope you can repurpose that handle. It sounds kind of fancy to just toss out.
I got a response back from Victor Muller of Feinwerkbau that the barrel twist rate is 450mm (right-hand)... which converts to 17.7165 inches.
That's interesting. Apparently the mop you used to "guesstimate" it before must have jumped the rifling in a spot or two and taken longer to complete it's half turn, giving you the wrong measurement. But at least now you know the actual twist rate. And straight from the factory, too. So it sounds like you're all ready to play with the Strelok software now. Have fun!
@jim-in-swmo Yep, ready to play around with it... but I don't think an exact BTR makes much of a difference at the distances that I shoot, which is seldom past 50 yards unless I'm just seeing if I can hit something (usually a steel tin can) at further distances.
I'm going to play around with the numbers just to see how the elevation clicks might vary.
But if you have to plug in a number, it may as well be as close an "accurate" one !
Was thinking about your mop and the bad measurement it gave you. I wonder if some of that bad measurement came from getting the mop started in the bore. That could have added to the overall measurement because you were probably a good inch past the beginning of the rifling when you started. I guess that would be a good reason to use a jag with a snug fitting patch. Besides being much harder for the jag/patch combo to jump the rifling, you would also be much closer to the beginning of the rifling in the bore when you start out.
Was thinking about your mop and the bad measurement it gave you. I wonder if some of that bad measurement came from getting the mop started in the bore. That could have added to the overall measurement because you were probably a good inch past the beginning of the rifling when you started. I guess that would be a good reason to use a jag with a snug fitting patch. Besides being much harder for the jag/patch combo to jump the rifling, you would also be much closer to the beginning of the rifling in the bore when you start out.
It could be... I tried a cleaning patch with the jag on the Beeman rod... it was a tight fit... probably too tight, that's why the thin rod got bent and broke off when I tried to straighten it.
Being the barrel grooves are so shallow, I figured the mop on the other sturdier rod would be tight enough to grab hold... which it did, since the rod was turning pretty easily... I inserted it from the loading breech end, since the other end has a Beeman muzzle break on it, and I didn't want to fool around with that end.
By the way the FWB300SU that I have is suppose to have the same BTR... as all their barrels have according to Victo, who was kind enough to tell me that as well.
