JSAR Raptor Tuning guide and thoughts.

[Motorhead]

Would lighter weight Marauder MDS hammers work?

Not likely ... the hammers overall length is critical to the triggers reset mechanics as is the cocking lug position.   with some fiddling you may be able to get something working but not sure.

[Jacob_M]

Took the raptor outside for the first time in a few days.

First shot over the chrony was 976 for 71fpe with the king heavy lol.

After that shot reg settled back down and the next 10 shots were all around 950fps.

Scary quiet , even at 71fpe!

[Luis Leon]

Took the raptor outside for the first time in a few days.

First shot over the chrony was 976 for 71fpe with the king heavy lol.

After that shot reg settled back down and the next 10 shots were all around 950fps.

Scary quiet , even at 71fpe!

Were you just checking the numbers? Or, are you also shooting targets? Would like to read your take on accuracy with slugs and/or pellets.

[Jacob_M]

I was checking numbers and also shooting casually at 100 yard 2 1/2 spinners.

It’s been a while since I shot at paper to check groups with the raptor. Now that I got a consistent tune, this will be the next step.

During my causal shooting I have had no problems hitting the 2 1/2 spinner , bottles, and pellet tins at 100 yards with 34gr jsb.

I have not found much success with NSA slugs. I need to give them another try.

I have had success with AVS slugs.

I need to order some of the promising slugs.

Really want to try HN, jsb and fx .25 slugs. Whenever they come out.

[ranchibi]

Jacob, have you tried any Griffin slugs? So far, the Griffin TC 20gr (freebies) have given me the tightest groups (1/3” CC) so far with me tuning for only 18gr JSB’s since I received my Raptor back with retrofitted adjustable regulator. Mike, the owner said these should group tighter with a 950fps (the speed he knows they perform best at) and I shot them at a little over 900.

[kamora187]

The reg creep has me a bit concerned, hope it settles down!

[Jacob_M]

The reg creep is not that bad. Now that my gun is tuned properly, the first shot was only 26fps higher. Then the rest were consistent.

I’ve done some reading and it seems like many guns across different brands need 1 shot to clear the reg of any creep.

[Bob Pratl]

The reg creep is not that bad. Now that my gun is tuned properly, the first shot was only 26fps higher. Then the rest were consistent.
I’ve done some reading and it seems like many guns across different brands need 1 shot to clear the reg of any creep.

I use to do a lot of benchrest shooting, with powder burns, and the first couple of shots where conditioners and to warm up the barrel before you would see consistent shots.
So now with air guns I just ignore the first of shots and treat them as conditioners. I'm sure that we would love to see no creep valves & regulators.
Even my expensive TIG and MIG gas regulators creep, to some degree, when setting on overnight.

[Luis Leon]

My Bantam Sniper HR (Huma Regulate) has been at 150 BAR since September 2019 and has not creeped at all. I’m lucky in that I get to shoot almost everyday. One of my routines is to take that first shot of the day. Whether at paper or a small object. Either at 40 or 50 yards. Which so far the gun passes with flying colors. During the course of my day I bring out the Bantam for a few shots here and there at small objects and can consistently get first round hits out to 66 yards. My gun continues to amaze me with its accuracy and consistency. I don’t believe creep is something you have to live with if you have a good regulator. All of my chronoed shot strings have SDs: under 10 FPS. Good luck with the Raptor.

[ranchibi]

Ernest Rowe, who is a wonderful tuner of pcp’s said that if your regulator is not set to a higher working pressure then the first couple of shots could be off a little in fps...

[triggertreat]

Set your velocity 5% below your max at a given set point and you won't have to worry so much about a little creep.  Be sure your hammer energy can handle the first shot after a fill without ambient temp issues.

[PSI-lbc]

** Also in this alternative set up I use TAPERED throat Transfer tubes to create sonic choking which also further help stabilize the output swings these easy opening valves experience.

Scott S

Is the smaller opening of the taper toward the barrel?   Sounds like "sonic choking" is similar to the "venturi effect" that surfboard makers create with angled fins " / \" to cause the water going between them to increase speed.

Found this when looking up sonic choking..wonder if something like this could be incorporated into the porting system of airguns..

[Jacob_M]

In my situation, the only way the reg creep affects me now is my first shot will be 20-30 fps higher than the rest of my string. Not a big deal to me.

Set your velocity 5% below your max at a given set point and you won't have to worry so much about a little creep.  Be sure your hammer energy can handle the first shot after a fill without ambient temp issues.

I found this very hard to do with the balanced valve. If I am currently shooting max 950fps and drop my fps down to + or - 905fps by adjusting the spring, I get a higher Extreme spread and more shot to shot variance.

If I keep it more tight, say 1-3% then ES is much better.

[Franklink]

I haven't played with my Raptor in it's current configuration to know if the adjustable reg creeps, so leaving that out of this and making general statements here.......

Most regs have some........performance issues that unregulated guns simply don't deal with.

My Veteran (the gun that everyone loves) has reg creep, or whatever else you like to call it. First shot will always be low fps. I know about it and blow off that first shot and life is good.

Regulation brings an increased level of complication and failure rate to a gun.

It's not a popular view, but for 99% of us airgunners, extreme spreads of less than 25 or so fps are not necessary, which means that neither are regulators. I'm taking about those of us that hunt or pest or even shoot paper in our yards. The current groundhog or starling doesn't care if it was killed with 12 more or less fps than the last one. And as far as impact points go, unless you're trying to make head shots on house sparrows at 125 yards, the difference in impact points due to fps changes within 25fps are neglible.

They do increase the tech level of a gun though, and open up further tinkering venues, all of which is the draw for some.

[mtnGhost]

I know it is NOT the way JSAR is doing it ... but having been around the balanced valves now nearly as long as anyone, likely manufactured more versions ( R&D ) than anyone have found that there are better ways and more stable miens to operate the firing system.     
JSAR has approached a One Hammer does all with a One Valve does all with one Transfer Port does all .... While this certainly eases the manufacturing process and creates a uniform tuning procedure across ALL CALIBERS. it falls short of being ideal 

Using a BUFFER hammer system where you have direct control over poppet lift is not without its shortcomings however.
Namely being UNDESIRABLE rebound if & when the hammer spring energy is too high and the hammer is violently slamming into the buffer ring.   * It is of my opinion and that of many I've spoken with that it's use is a Crutch to allow having some control of the valves HEAVY BREATHING attributes.

My work around and how my personal guns using these valves ( versions of etc ... ) has been to use MUCH lighter hammers and control them via SSG spring devices.
* This also has a downside ... We loose the WIDE tuning range afforded by the factory configuration, but GAIN a lot more control being one can change hammer weight and spring force to a specific caliber and power setting.  This eliminates the need for a buffer with a result the guns are far more stable being also a whole lot easier to get a solid tune.
** Also in this alternative set up I use TAPERED throat Transfer tubes to create sonic choking which also further help stabilize the output swings these easy opening valves experience.

Scott S

I'm always concerned about the wear and tear aspect of buffering. Especially in circumstances where I've fallen off the reg and not realized it. I hunt more than anything else, and probably 80% of that is at night.

** Also in this alternative set up I use TAPERED throat Transfer tubes to create sonic choking which also further help stabilize the output swings these easy opening valves experience.

Scott S

Is the smaller opening of the taper toward the barrel?   Sounds like "sonic choking" is similar to the "venturi effect" that surfboard makers create with angled fins " / \" to cause the water going between them to increase speed.

Found this when looking up sonic choking..wonder if something like this could be incorporated into the porting system of airguns..

I ended up doing something like that with the valves that I made for my Taipan Vet. The first few that I made were just operating on the principals of opening up the porting for overcoming airflow restrictions, which yielded me around 25-30FPS (.217 / 25gr H&N slugs). When I incorporated multi-stage /\'s, velocity increased to almost 100FPS over the factory system. I was blown away, thinking I'd only see maybe 50 lol

That leads me to ask about the ideal porting sizes for the .30cal Raptors. I've decided to stick with ammo along the lines of Dale's 62gr Varmint Knockers (BHN-7) with the JSAR mags and given the smaller plenum I need to optimize the rifle for this caliber (I have plans for running it in smaller calibers btw).

[Motorhead]

In case you missed this ... it may anwser some questions

See: https://www.gatewaytoairguns.org/GTA/index.php?topic=165159.msg155844248#msg155844248

[mtnGhost]

(I have plans for running it in smaller calibers btw).

Meant to say that I have NO plans running smaller calibers lol

In case you missed this ... it may anwser some questions

See: https://www.gatewaytoairguns.org/GTA/index.php?topic=165159.msg155844248#msg155844248

Good info! I've been dying to get a look inside on this Mini, but the o-rings that I was missing arrived in the mail today so I'm all in.

Hoping I'll have better luck in actually being able to remove the barrel with it disassembled. I don't think this one was turned down just right, it wouldn't budge more than a 1/2" when I tried to remove it

[ranchibi]

In my situation, the only way the reg creep affects me now is my first shot will be 20-30 fps higher than the rest of my string. Not a big deal to me.

Set your velocity 5% below your max at a given set point and you won't have to worry so much about a little creep.  Be sure your hammer energy can handle the first shot after a fill without ambient temp issues.

I found this very hard to do with the balanced valve. If I am currently shooting max 950fps and drop my fps down to + or - 905fps by adjusting the spring, I get a higher Extreme spread and more shot to shot variance.

If I keep it more tight, say 1-3% then ES is much better.

Jacob, very true about the balance valves..they like to BREATHE! LOL! That’s what they were made to do, shoot fast. I too cannot make mine shoot much slower with any consistency. I should just shoot heavy but I really like the 18gr JSB as they are relatively inexpensive but have to be shot over 950 to get consistent fps results which is paramount to consistent accuracy...even faster is better. Throwing slugs or 25gr JSB’s through her quiets her report down even at faster speeds.

[mtnGhost]

Cool, I got inside my Mini .30 finally  I got several things done that were on my ToDo list, such as chucking my probe on my lathe to hand polish some of the chatter marks that have been bugging me (and possibly adding to my jamming issues with small slugs).

I also FINALLY got my barrel off. First thing I noticed was my barrel TP was a little off-center from the block ports, possibly from when I attempted to remove it the first time - but my witness marks were in perfect alignment ‍♂️ Also, there was indeed a little high point on the breech side of the barrel near the second grub screw divot that was making it a little too tight for the block, so I also hand polished the entire section turned down to 0.5000", and now it's not as painful to install / remove. Spent 2 hours polishing the barrel, cut a slightly deeper throat in the breech, and got it all put back together.

Repressurized it to 2K PSI and shot a few test shots, and nearly went deaf!!! I figured it would quiet back down once I turned the reg up some and retuned. I decided to stop around 2350psi for the 50gr JSBs. I loaded up a couple of mags with sorted pellets, and got it shooting 888 (literally 888 each shot), but it is definitely a bit louder now. Like a higher pitch than when I had it tuned like this before.

Now the one thing that I'm probably doing differently is I'm not leaning on the buffer much at all. The last step that I take in my tuning process is turning it in slightly and relying on my hammer settings to do all of the work. It used to have a deeper puff sound, but now my ears are ringing

[ranchibi]

Cool, I got inside my Mini .30 finally  I got several things done that were on my ToDo list, such as chucking my probe on my lathe to hand polish some of the chatter marks that have been bugging me (and possibly adding to my jamming issues with small slugs).

I also FINALLY got my barrel off. First thing I noticed was my barrel TP was a little off-center from the block ports, possibly from when I attempted to remove it the first time - but my witness marks were in perfect alignment ‍♂️ Also, there was indeed a little high point on the breech side of the barrel near the second grub screw divot that was making it a little too tight for the block, so I also hand polished the entire section turned down to 0.5000", and now it's not as painful to install / remove. Spent 2 hours polishing the barrel, cut a slightly deeper throat in the breech, and got it all put back together.

Repressurized it to 2K PSI and shot a few test shots, and nearly went deaf!!! I figured it would quiet back down once I turned the reg up some and retuned. I decided to stop around 2350psi for the 50gr JSBs. I loaded up a couple of mags with sorted pellets, and got it shooting 888 (literally 888 each shot), but it is definitely a bit louder now. Like a higher pitch than when I had it tuned like this before.

Now the one thing that I'm probably doing differently is I'm not leaning on the buffer much at all. The last step that I take in my tuning process is turning it in slightly and relying on my hammer settings to do all of the work. It used to have a deeper puff sound, but now my ears are ringing

Gino, very nice work! I wish I had those machining skills! Raptor’s are similar to Marauders and here is a link to tuning one different ways if you didn’t already know. Your sound signature sounds like a strong hammer spring tension with a short striker hit, hence the louder crisp report, with these adjustments, your fps consistency and efficiency will be excellent. With a light hammer spring adjustment and longer striker hit you get the much lower sound signature but consistency and efficiency suffers a little. You can tune in between easier with your .30...I have not much leeway with mine being a .22 with the balance valve and large plenum. Anyway, glad you have yours shooting well!

https://www.airgunnation.com/topic/tuning-a-marauder-what-to-adjust-and-where-to-start/