Thats a great question. It gets a little complex to explain it in detail but in general velocity and the relationship to twist rate scale with drag or oncoming air pressure. Higher speed can help a little bit but it can also bring its own issues. For example if the slug being shot is stable at 950fps and you increase the velocity to 1050fps you should get better stability at distance. velocity will always decay faster then rotation so stability should improve down range. This can work for hunting applications and yield really good terminal performance. Thats because slugs on the edge of stability will tumble when they hit and that is usually much better then a Hollow point. Trying to cheat stability in this way is not ideal for long range target shooting or pression shooting. Generally you will see no improvement in ballistic coefficient or wind deflection with slugs that are at the extreme end of the stability scale. So depending on what the end goal is there could be a use case for this approach. Generally my personal thoughts would be to step down the weight slightly to a optimal weight range and shoot faster. i reread your comment and there should be no negative effects from shooting faster if you already have good stability, if anything stability will improve. If your slug is in spec for your twist rate velocity should have very little effect on stability or accuracy. from there it gets into tuning but if we had a perfectly tunable airgun you should be able to shoot anywhere from 650fps to 1650fps and get similar results with the same slug. Hopfully that helps a little let me know if you have any other questions

@@griffinairgunammo7518 great reply! The reason I asked is because I have an MCAR .457 on order. It has a 1:28 twist rate and a 38" long barrel. From my research, I'm seeing that the 280-330 grains "may" be it's sweet spot. But I want to shoot heavier 350-388 grains, and I want to shoot them fast, 950 fps. With a slow twist rate, stability was in question for me, because I'm already adding weight/length, and then on top of that turning up the reg/speed. It all really had me wondering if my approach is gonna be an unstable mess, lol.

@@jarroldharrell i just punched the numbers into my ballistic calculator. a 350gn boat tail is in the sweet spot for a 1/28 twist rate . you should be able to run 380gn also. large calibers dont require as much twist to stabilize. You can use Strelok ballistic calculator to find the stability rating for any twist rate and slug combo. This can also show the changes velocity can make to stability. This uses the common miller twist formula which is a simple model. This will give you a stability factor, the minimum SF required for a slug to fly nose fist is 1.0 its normally recommended to have a SF of 1.25-1.5 or better for optimal ballistics . If the SF is under 1.25 and weight or length is added BC will not increase relative to sectional density. This indicates the limit of the twist rate for a given slug. If you have more questions on this topic you can find my phone number on my website at griffinairguns.com

What slug would you recommend for my .25 cal LCS SK-19? It loves 34 Gr FX pellets and tack drives them out to 75 yards but this Lothar Walther Match Grade Polygonal Choked barrel doesn’t seem to like slugs. Every slug tried so far from NSA, and JSB looks like #4 buck round at 25 yards. Never tried yours or FX Hybrids. This hammerless system is a powerhouse and super tunable quickly but the twist rate, rifling type, and choke I think are my problem overall. The .250 cal slugs all seem to be slightly loose in the titanium magazine where the pellets are snug of that helps answer my question for what slug would work. Thanks if you can answer this question.

Hi, I got a mussel adapter from talon tunes and the donnyfl moderator from utah airguns. really you just need the mussel adapter then you can use any brand moderator you like.

Are you talking about the Huban pistol? In .22 the 30 and 34 grain boat tails should fit. in .25 they wont fit. boat tail may by a little heavy for a pistol.

@@griffinairgunammo7518 yeah I have the .25 though

Thanks for the reply! They’re the best for the gauntlet 30 nothing compares.

@@leadslinger5130 Hey man, nice to hear you are still alive LOL You are such a helpful person and I can only say thanks for the help you have given me in the past.

Yeah the 35 cal Impact is not made for slugs. If you want a 357 for slugs you really want something with more power like a benjamin bulldog or a Texan. 357 slug guns need to be over 250 fpe in my opinion.

Hello Derrick, I have had good reports from hunters with that slug in their mk2 and mk3's. I won't clame it will shoot 1 hole groups but they are great for hunting. A customer just emailed me today saying he took his second deer with them if that help. The 88gn flat base also works.

@@griffinairgunammo7518 Good information. I need it to be sub MOA within say.....75 yards maybe.

@@derrickmitchell39dm I'll be completely honest I have not had a chance to test them my self so I can't say. If you want I could make you sample pack with a 357 88gn flat , 71gn dish LDC and 358 of the same. Those are the only 4 I make that will fit fx mags. To be honest from my emails It sounds like lots of people are struggling to get sub moa with any slugs with 357 impact.

@@griffinairgunammo7518 this is ridiculous. Yes I'll try a sample pack and report my findings to you.

I love my condor. They are great rifles. The 44gn cup base large hollow points are the slug for the .25 cal. They shoot like a lazer.

I own both too!

Yes 1/16 is plenty for slugs in .357. Larger calibers dont need as much twist to stabilize. The only calibers that have problems is the smaller calibers depending on the slug size. I'm as this video about 257 because there are some really powerful 25 cal rifles. Lots of people where tring to shoot to slugs that where to heavy for there barrels. As slugs get heavier they get longer the longer the slug gets the more twist it general needs.

@@leadslinger5130 Good Information. I contacted TJ to get a price, availablility and further recommendations. Thanks

@@derrickmitchell39dm are you making a custom rifle? If you have a decent amount of power to play with and a good size breach a lot of hunter like the 135gn boat tail LDC

I would go with a 52 to 54 grain dish base. Or a 48 to 50 grain flat base LDC they are better for hunting and are bigger in length for there weight.

Yes we have 2 slugs that we have really good feedback from. The .357 88 grain flat base and the 71 grain dish base LDC. Those are the only 2 I recommend for the impact.

@@griffinairgunammo7518 ordering in 20 min.

For the FX Impact .35 mk2 with the 1:24 barrel a 81 or 82 grain slug would be perfect. Right?

@@derrickmitchell39dm the 88 grain flat base is the best size for the impact's also the 71grain dish base LDC. Those are the only 2 that have worked really well. The 71 grain dish base LDC is the best for hunting.

@@leadslinger5130 ok cool. Thanks!😃😄

I really like the condor a lot after playing with it for a while and moding the hell out of it. It is more sensitive to harmonics then most other rifles but its mostly a side effect of the power it makes. And for the most part it can all be handled by changing bipod location. Also it unregulated so the harmonics will change as the fill pressure changes. It shoots slugs well and makes more power then anything else in the same caliber. In .25 cal mine makes 100fpe easy and can max out at 130fpe with 65gn baot tail. So if need raw hunting power then there is no better choice in my opinion if you really want super tight groups then there are better target guns but you will probably pay a bit more. It's a great airgun for the price.

The lab radar is great. Our leishy 2 is amazing. They shoot slugs very well to it just hard to load them in the mag and get the mag In the gun without the slugs falling out. But once the mag is in the slugs work great. Thanks for watching!

Thanks for Sharing the link, I have been working on the last email you sent I just haven't had time to it down lately.

@@griffinairgunammo7518 That's OK Ben. Keep in touch whenever you can, I have a few more questions. :)

Is it a 25-20 barrel or is it one of the barrels that came on the old school marauders? In any case the 25-20 barrels are .257's and a 40gn slug would work decent at that power level. I'm not to sure about the green mountain barrel that was on the marauder but I would try regulator. 250 slugs in that barrel with a slightly lighter slug at around 36gn.

JBM calculator work well. 8.8 seem very high. What type of ammo are you useing? I haven't tested anything with a SF that high personally but with a 1/10 TR you can shoot up to 115 grain slugs with no issues. I usually look for a stability factor of 1.7 or better. Having to high of a SF can cause excessive spin drift and deflection in wind. If you are having issues with wind drift or spin drift then I would say use heavier slugs. You can also use longer ogive slugs with that twist rate that many other barrels wont shoot well. For example I have a green mountain. 5.45 barrel with a 1/8 twist and that barrel will shoot a 65gn 6s 22 cal wich basically the same thing an AR 15 uses, normal airgun barrels will shoot then sideways. Let me know if you have more questions

@@griffinairgunammo7518 Hello again, It seems you have a wealth of knowledge and experience on this subject. I truly appreciate you giving me the time in answering my questions. For the moment, I am swagging my own slugs with the following spec's. Total length is 8.6mm. Bearing surface is 6mm. 36 gr in weight but I can make 40 gr as well. Slug is 6.4mm thick and engages the rifling quite well. Type is a TC style with fairly large tapered cavity on the tail. (Not flat or cup) Tail thickness is around 1mm for no distortion. Slug is not a hollow point but has a small flat where the hollow area would be. Shooting at 850 fps. As previously said, Twist Rate is 1:10" Accuracy is horrible. Shoots slugs everywhere and will not group. At 35 mtrs, I can actually miss a football. There's obviously a serious problem somewhere...

Hey buddy sorry for the slow response. So from what I gather your slug .6.4 mm(.251 inches) that is probably the issue. I would try a .257 slug and see if that fixes the problem. I know that not what you want to hear since you bought your die but the up side is, that diameter will work good for most stock airguns and it's a good wieght for a stock airgun also. I'm curious what gun this barrel is on and how much power do you gave to play with. There is one thing you could try and that's powder coating your slugs it's kind of a pain but it will add a few thousandths of an inch to your slug diameter. If you have the power to shoot 100+ FPE YOUR 1/10 barrel will shoot a very high bc slug. I would try something in .257 around 75 grain to start with.